[Clang][Sema] Unreachable executed when using `opencl_generic` attribute in SYCL

[Maetveis]

The following code, when compiled with clang -fsycl test.cpp

// test.cpp
int [[clang::opencl_generic]] *a;

makes clang crash with the message:

Invalid address space
UNREACHABLE executed at /root/llvm-project/llvm/tools/clang/lib/Sema/SemaType.cpp:6577!

See it on Compiler Explorer

Clang should not crash, it should either accept or reject the input with a proper message.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Mészáros Gergely (Maetveis)

The following code, when compiled with `clang -fsycl test.cpp` ```cpp int [[clang::opencl_generic]] *a; ``` makes clang crash with the message: > Invalid address space > UNREACHABLE executed at /root/llvm-project/llvm/tools/clang/lib/Sema/SemaType.cpp:6577!

See it on Compiler Explorer

Clang should not crash, it should either accept or reject the input with a proper message.