It may likely show up as garbage, as it's not a real local variable
(allocated by caller, address mostly passed in a register); e.g., this
happens on Win64 with the VS debugger ('expression is not an address' or
something along these lines), but at least output *some* DI.
We may be able to fix this and similar issues with LLVM 7 and new
intrinsic llvm.dbg.addr().
There's a new need to access a class' vtable symbol, see dlang/dmd#8362.
Use it as alias to the actual vtable symbol with different type (dummy:
`i8*`, actual: `[N x i8*]`) and mangled name.
I tried matching the special symbol's mangled name and using an
appropriate static array front-end type for it, but then casting the
symbol address for the assignment leads to issues if the ctor is @safe.
So I decided to handle it in DtoSymbolAddress().
Unfortunately, this seems not to solve the extern(C++) issues exposed by
LDC self-compilation yet.
The AST now features special-ref result variables (storage classes:
ref, temp, result) after rewriting out contracts; from dmd/func.d:
/* out(id1) { statements1... }
* out(id2) { statements2... }
* ...
* becomes:
* out(__result) { { ref id1 = __result; { statements1... } }
* { ref id2 = __result; { statements2... } } ... }
*/
We are talking about the `id1` and `id2` variables here.
There's an existing assertion that we don't set a special-ref variable's
lvalue (T**) to the sret pointer (T*) which was already triggered when
compiling Phobos without unittests.
Making it obvious which of the two operations is performed, reducing
call args and making sure a global isn't defined multiple times via
`defineGlobal()`.
The only [intended] functional change is in gen/trycatchfinally.cpp,
where I inserted a check for an existing __cpp_type_info_ptr global when
emitting a catch for C++ exceptions.
Not all type declarations yet (e.g., some TypeInfo subtypes are still
accessed directly), but those already wrapped as LazyType in the
gen/runtime.cpp module (with check and proper error msg in case object.d
doesn't contain a required declaration).
