On Thursday, 21 January 2016 at 04:42:00 UTC, Rikki Cattermole
wrote:
On 21/01/16 5:21 PM, Anon wrote:
Seeing the recent extern(C++) threads, and much concern
therein, I'd
like to propose DIP87: http://wiki.dlang.org/DIP87
Destroy to your heart's content.
It was great until I saw:
extern(auto, "myMoveTo:")
After all:
extern(C/C++/D/Objective-C[, string])
Is that string meant for raw mangling or effect mangling in the
form of selector?
Just no, leave @selector alone I think.
I don't know ObjC, so I had to wing it on the details there. The
strings in
extern(<Foo>, "str") would get sent through Foo's mangler. For
ObjC, I currently imagine those strings forming the selector,
much the same way it is specified through @selector. That ObjC's
mangling mostly consists of 's/:/_/g' is irrelevant. I want *all*
language binding to happen with a uniform interface. No more
one-off hacks for a particular language (which is exactly what
extern(C++,ns) and @selector are).
You have the same problem with c++ namespaces.
I don't see a problem. You'll have to be more specific.
Perhaps this is slightly wrong.
extern(string)
Is the only way to force a specific mangling.
There is no extern(string) in this proposal, nor is there a way
to force a specific mangling, which (AFAIK) was only introduced
to allow linking to C symbols that happened to be keywords.
Where as extern(C/C++/D/Objective-C[, string])
with the string altering in C++ and Objective-C mode.
It mangles regardless. Any and all of the extern(<Foo>) modes
mangle. That C's mangling is to just return the input string is
irrelevant.
So the only difference is extern(string) vs pragma(mangle,
string)
Little harder sell, but I think might be worth it for cleaning
up the language.
The difference is that it can mangle symbols correctly, even if
the symbol is a D keyword.
Currently:
extern(C++) pragma(mangle, "delegate") int delegate_();
...yields a mangled name of "delegate", and there is no way to
get the compiler to mangle the symbol correctly. Meaning you have
to (ab)use pragma(mangle) and provide it with the full mangled
name yourself. And `version()` it appropriately to deal with
gcc/clang vs MSVC/DMC mangling.
With this DIP:
extern(C++, "delegate") int delegate_();
... would yield a mangled name of "_Z8delegatev" (or similar).
I thought I did a good enough job of explaining that in the DIP
so I wouldn't have to here.
