[SYCL][Clang] Add sentinel value to kernel_args_sizes

Add sentinel value to compiler generated array kernel_args_sizes
in integration header to avoid warnings about empty arrays. This
array is used to hold the number of elements in each kernel. This
PR changes the type to int to add a sentinel value of -1.

Author: elizabethandrews

clang/lib/Sema/SemaSYCL.cpp

@@ -7052,11 +7052,15 @@ void SYCLIntegrationHeader::emit(raw_ostream &O) {
   O << "  \"\",\n";
   O << "};\n\n";
 
-  O << "static constexpr unsigned kernel_args_sizes[] = {";
+  O << "static constexpr int kernel_args_sizes[] = {";
   for (unsigned I = 0; I < KernelDescs.size(); I++) {
     O << KernelDescs[I].Params.size() << ", ";
   }
+  // Add a sentinel to avoid warning if the collection is empty
+  // (similar to what we do for kernel_signatures below).
+  O << "-1, \n";
   O << "};\n\n";
+
   O << "// array representing signatures of all kernels defined in the\n";
   O << "// corresponding source\n";
   O << "static constexpr\n";

clang/test/CodeGenSYCL/int-header-empty-signatures.cpp

@@ -10,7 +10,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {0, -1
 
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {

clang/test/CodeGenSYCL/integration_header.cpp

@@ -25,7 +25,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 //
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {5, 3, 2, 8, 3, 0, -1,
 //
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {

clang/test/CodeGenSYCL/kernel-param-acc-array-ih.cpp

@@ -18,7 +18,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {2, -1,
 
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {

clang/test/CodeGenSYCL/kernel-param-member-acc-array-ih.cpp

@@ -18,7 +18,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {2, -1,
 
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {

clang/test/CodeGenSYCL/kernel-param-pod-array-ih.cpp

@@ -19,7 +19,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {1, 1, 1, -1,
 
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {

clang/test/CodeGenSYCL/union-kernel-param-ih.cpp

@@ -18,7 +18,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {1, -1,
 
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {

clang/test/CodeGenSYCL/wrapped-accessor.cpp

@@ -15,7 +15,7 @@
 // CHECK-NEXT:   ""
 // CHECK-NEXT: };
 
-// CHECK: static constexpr unsigned kernel_args_sizes[] = {
+// CHECK: static constexpr int kernel_args_sizes[] = {1, -1,
 
 // CHECK: static constexpr
 // CHECK-NEXT: const kernel_param_desc_t kernel_signatures[] = {