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

[John McCall via Phabricator via cfe-commits]

rjmccall added inline comments.


================
Comment at: lib/Sema/TreeTransform.h:5363
+    if (ResultType.getAddressSpace() != LangAS::Default &&
+        (ResultType.getAddressSpace() != LangAS::opencl_private)) {
       SemaRef.Diag(TL.getReturnLoc().getBeginLoc(),
----------------
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.


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  https://reviews.llvm.org/D62584/new/

https://reviews.llvm.org/D62584