[HLSL][SPIRV] Handle uint type for spec constant

The testing only tried `unsigned int` and not `uint`. We want to
correctly handle these surgared types as specialization constants.

Author: s-perron

clang/lib/Sema/SemaHLSL.cpp

@@ -120,7 +120,7 @@ static ResourceClass getResourceClass(RegisterType RT) {
   llvm_unreachable("unexpected RegisterType value");
 }
 
-static Builtin::ID getSpecConstBuiltinId(QualType Type) {
+static Builtin::ID getSpecConstBuiltinId(const Type *Type) {
   const auto *BT = dyn_cast<BuiltinType>(Type);
   if (!BT) {
     if (!Type->isEnumeralType())
@@ -654,7 +654,8 @@ SemaHLSL::mergeVkConstantIdAttr(Decl *D, const AttributeCommonInfo &AL,
 
   auto *VD = cast<VarDecl>(D);
 
-  if (getSpecConstBuiltinId(VD->getType()) == Builtin::NotBuiltin) {
+  if (getSpecConstBuiltinId(VD->getType()->getUnqualifiedDesugaredType()) ==
+      Builtin::NotBuiltin) {
     Diag(VD->getLocation(), diag::err_specialization_const);
     return nullptr;
   }
@@ -3920,7 +3921,8 @@ bool SemaHLSL::handleInitialization(VarDecl *VDecl, Expr *&Init) {
     return false;
   }
 
-  Builtin::ID BID = getSpecConstBuiltinId(VDecl->getType());
+  Builtin::ID BID =
+      getSpecConstBuiltinId(VDecl->getType()->getUnqualifiedDesugaredType());
 
   // Argument 1: The ID from the attribute
   int ConstantID = ConstIdAttr->getId();

clang/test/AST/HLSL/vk.spec-constant.usage.hlsl

@@ -64,6 +64,17 @@ const unsigned short ushort_const = 10;
 [[vk::constant_id(6)]]
 const unsigned int uint_const = 12;
 
+// CHECK: VarDecl {{.*}} uint_const_2 'const hlsl_private uint':'const hlsl_private unsigned int' static cinit
+// CHECK-NEXT: CallExpr {{.*}} 'unsigned int'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'unsigned int (*)(unsigned int, unsigned int) noexcept' <FunctionToPointerDecay>
+// CHECK-NEXT: DeclRefExpr {{.*}} 'unsigned int (unsigned int, unsigned int) noexcept' lvalue Function {{.*}} '__builtin_get_spirv_spec_constant_uint' 'unsigned int (unsigned int, unsigned int) noexcept'
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'unsigned int' <IntegralCast>
+// CHECK-NEXT: IntegerLiteral {{.*}} 'int' 6
+// CHECK-NEXT: ImplicitCastExpr {{.*}} 'unsigned int' <IntegralCast>
+// CHECK-NEXT: IntegerLiteral {{.*}} 'int' 12
+[[vk::constant_id(6)]]
+const uint uint_const_2 = 12;
+
 
 // CHECK: VarDecl {{.*}} ulong_const 'const hlsl_private unsigned long long' static cinit
 // CHECK-NEXT: CallExpr {{.*}} 'unsigned long long'