[CUDA][HIP] Fix checking dependent initalizer

[yaxunl]

Summary

Defer constant checking of dependent initializer to template instantiation
since it cannot be done for dependent values.

This is separated from https://reviews.llvm.org/D95560

[tra]

clang/lib/Sema/SemaCUDA.cpp

538

Nit, no need for () any more, as all parts of the expression ar ||-ed together.

clang/test/SemaCUDA/dependent-device-var.cu

9

So, the patch now allows using type-dependent constant expressions now.
I'd add a comment highlighting this. It's not always obvious that the test's purpose is to verify the absence of an error.

[yaxunl]

clang/lib/Sema/SemaCUDA.cpp

538

will do

clang/test/SemaCUDA/dependent-device-var.cu

9

will do

clang/lib/Sema/SemaCUDA.cpp

if (const CXXConstructExpr *CE = dyn_cast<CXXConstructExpr>(Init))
       AllowedInit =
           isEmptyCudaConstructor(VD->getLocation(), CE->getConstructor());
     // We'll allow constant initializers even if it's a non-empty
     // constructor according to CUDA rules. This deviates from NVCC,
     // but allows us to handle things like constexpr constructors.
     if (!AllowedInit &&
         (VD->hasAttr<CUDADeviceAttr>() || VD->hasAttr<CUDAConstantAttr>())) {
       auto *Init = VD->getInit();
+      // isConstantInitializer cannot be called with dependent value, therefore
+      // we skip checking dependent value here. This is OK since
+      // checkAllowedCUDAInitializer is called again when the template is
+      // instantiated.
       AllowedInit =
-          ((VD->getType()->isDependentType() || Init->isValueDependent()) &&
-           VD->isConstexpr()) ||
+          VD->getType()->isDependentType() || Init->isValueDependent() ||
           Init->isConstantInitializer(Context,
                                       VD->getType()->isReferenceType());
     }
 
     // Also make sure that destructor, if there is one, is empty.
     if (AllowedInit)
       if (CXXRecordDecl *RD = VD->getType()->getAsCXXRecordDecl())
         AllowedInit =

clang/test/SemaCUDA/dependent-device-var.cu

+// RUN: %clang_cc1 -fsyntax-only -verify=host,com -x hip %s
+// RUN: %clang_cc1 -fsyntax-only -fcuda-is-device -verify=dev,com -x hip %s
+
+#include "Inputs/cuda.h"
+
+template<typename T>
+__device__ int fun1(T x) {
+  // Check type-dependent constant is allowed in initializer.
+  static __device__ int a = sizeof(x);
+  static __device__ int b = x;
+  // com-error@-1 {{dynamic initialization is not supported for __device__, __constant__, __shared__, and __managed__ variables}}
+  return  a + b;
+}
+
+__device__ int fun1_caller() {
+  return fun1(1);
+  // com-note@-1 {{in instantiation of function template specialization 'fun1<int>' requested here}}
+}