[clang] [Clang/AMDGPU] Zero sized arrays not allowed in HIP device code. (PR #113470)

[Eli Friedman via cfe-commits]

================
@@ -2259,6 +2259,17 @@ QualType Sema::BuildArrayType(QualType T, ArraySizeModifier ASM,
              isSFINAEContext() ? diag::err_typecheck_zero_array_size
                                : diag::ext_typecheck_zero_array_size)
             << 0 << ArraySize->getSourceRange();
+
+        // zero sized static arrays are not allowed in HIP device functions
+        if (LangOpts.HIP && LangOpts.CUDAIsDevice) {
----------------
efriedma-quic wrote:

I'm not sure you're diagnosing this in the right place; BuildArrayType gets called at the point we parse the type, not the variable, so you can easily avoid the diagnostic using something like the following:

```
typedef float floatarr[0];
__global__ void global_fun() {
    floatarr array;
}
```

https://github.com/llvm/llvm-project/pull/113470