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

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Vigneshwar Jayakumar (VigneshwarJ)

<details>
<summary>Changes</summary>

Added diagnosis to throw error when zero sized arrays are used in the HIP device code. SWDEV-449592

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


3 Files Affected:

- (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+1-1) 
- (modified) clang/lib/Sema/SemaType.cpp (+11) 
- (added) clang/test/SemaHIP/zero-sized-device-array.hip (+25) 


``````````diff
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 8e4718008ece72..b5fad40294c368 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6251,7 +6251,7 @@ def err_typecheck_invalid_restrict_invalid_pointee : Error<
 def ext_typecheck_zero_array_size : Extension<
   "zero size arrays are an extension">, InGroup<ZeroLengthArray>;
 def err_typecheck_zero_array_size : Error<
-  "zero-length arrays are not permitted in %select{C++|SYCL device code}0">;
+  "zero-length arrays are not permitted in %select{C++|SYCL device code|HIP device code}0">;
 def err_array_size_non_int : Error<"size of array has non-integer type %0">;
 def err_init_element_not_constant : Error<
   "initializer element is not a compile-time constant">;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 6387fe9f1129ba..3f940102da51d2 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -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) {
+          auto *FD = dyn_cast_or_null<FunctionDecl>(CurContext);
+          if (FD && (FD->hasAttr<CUDADeviceAttr>() ||
+                     FD->hasAttr<CUDAGlobalAttr>())) {
+            Diag(ArraySize->getBeginLoc(), diag::err_typecheck_zero_array_size)
+                << 2 << ArraySize->getSourceRange();
+            return QualType();
+          }
+        }
       }
 
       // Is the array too large?
diff --git a/clang/test/SemaHIP/zero-sized-device-array.hip b/clang/test/SemaHIP/zero-sized-device-array.hip
new file mode 100644
index 00000000000000..31fc943f5ae75b
--- /dev/null
+++ b/clang/test/SemaHIP/zero-sized-device-array.hip
@@ -0,0 +1,25 @@
+// REQUIRES: amdgpu-registered-target
+// RUN:  %clang_cc1 -fsyntax-only -x hip -fcuda-is-device -verify -triple amdgcn %s
+#define __device__ __attribute__((device))
+#define __host__ __attribute__((host))
+#define __global__ __attribute__((global))
+#define __shared__ __attribute__((shared))
+
+__global__ void global_fun() {
+    float array[0];  // expected-error {{zero-length arrays are not permitted in HIP device code}}
+}
+
+// should not throw error for host side code.
+__host__ void host_fun() {
+    float array[0];
+}
+
+__host__ __device__ void host_dev_fun()
+{
+    float array[0]; // expected-error {{zero-length arrays are not permitted in HIP device code}}
+}
+
+__device__ void device_fun()
+{
+    __shared__ float array[0]; // expected-error {{zero-length arrays are not permitted in HIP device code}}
+}

``````````

</details>


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