[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())
----------------
GorNishanov wrote:
> 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);
>     }
>   }
> ```
I think promise constructor argument preview is also missing the implicit object parameter.


Repository:
  rC Clang

https://reviews.llvm.org/D42606