[PATCH] D62584: [OpenCL][PR42033] Deducing addr space with template parameter types

[Anastasia Stulova via Phabricator via cfe-commits]

Anastasia marked an inline comment as done.
Anastasia added inline comments.


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Comment at: lib/Sema/TreeTransform.h:5363
+    if (ResultType.getAddressSpace() != LangAS::Default &&
+        (ResultType.getAddressSpace() != LangAS::opencl_private)) {
       SemaRef.Diag(TL.getReturnLoc().getBeginLoc(),
----------------
Anastasia wrote:
> rjmccall wrote:
> > Anastasia wrote:
> > > I am trying to be a bit more helpful here although I am not sure if we should instead require explicit template parameter and fail the template deduction instead.
> > > 
> > > Basically, do we want the following code to always require specifying template argument explicitly:
> > > 
> > > 
> > > ```
> > > template <class T>
> > > T xxx(T *in) {
> > >   T *i = in;
> > >   return *i;
> > > }
> > > 
> > > __kernel void test() {
> > >   int foo[10];
> > >   xxx<int>(&foo[0]); // if we deduce type from foo, it ends up being qualified by __private that we currently diagnose. However private is default (implicit) address space for return type so technically there is no danger in just allowing xxx(&foo[0])
> > > }
> > > ```
> > Implicitly ignoring all address-space qualifiers on the return type seems like the right thing to do; I don't think it needs to be limited to `__private`.  That's probably also the right thing to do for locals, but I'm less certain about it.
> Just to clarify by "Implicitly ignoring" you mean ignoring if the templ parameters were deduced?
> 
> Although I am a bit concerned about allowing other than `__private` address spaces in return types as we reject them in return types of functions generally. Would it not be somehow inconsistent?
Ok, I have removed the diagnostic completely. At least we don't seem to generate any incorrect IR.


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