[PATCH] D42606: [Coroutines] Use allocator overload when available

[Gor Nishanov via Phabricator via cfe-commits]

GorNishanov added inline comments.


================
Comment at: lib/Sema/SemaCoroutine.cpp:1062
+  // an argument list."
+  for (auto *PD : FD.parameters()) {
+    if (PD->getType()->isDependentType())
----------------
This does not implement TS specified behavior for non static member functions:

[dcl.fct.def.coroutine]/7 states that  an argument list is build up as follows:

>   The first argument is the amount of space requested, and has type std::size_t. The lvalues p1 ... pn are the succeeding arguments. 

Where p1 ... pn are defined earlier in

[dcl.fct.def.coroutine]/3 as:

> For a coroutine f that is a non-static member function, let P1 denote the type of the implicit object parameter (13.3.1) and P2 ... Pn be the types of the function parameters; otherwise let P1 ... Pn be the types of the function parameters. 

Essentially for non-static member functions, we need to insert implicit object parameter.

Note that lookupPromiseType in SemaCoroutine.cpp when building specialization of `std::experimental::coroutine_traits<...>` includes implicit object parameter:

```
  // If the function is a non-static member function, add the type
  // of the implicit object parameter before the formal parameters.
  if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
    if (MD->isInstance()) {
      // [over.match.funcs]4
      // For non-static member functions, the type of the implicit object
      // parameter is
      //  -- "lvalue reference to cv X" for functions declared without a
      //      ref-qualifier or with the & ref-qualifier
      //  -- "rvalue reference to cv X" for functions declared with the &&
      //      ref-qualifier
      QualType T =
          MD->getThisType(S.Context)->getAs<PointerType>()->getPointeeType();
      T = FnType->getRefQualifier() == RQ_RValue
              ? S.Context.getRValueReferenceType(T)
              : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
      AddArg(T);
    }
  }
```


Repository:
  rC Clang

https://reviews.llvm.org/D42606