[SYCL] Propagate inline namespace to integration header.

Previously, if kernel name was declared inside inline
namespaces the compilation failed since 'inline'
keyword wasn't propagated to integration header.
This patch fixes this issue.

Signed-off-by: Ilya Stepykin <[email protected]>

Author: Ilya Stepykin

clang/lib/Sema/SemaSYCL.cpp

@@ -1412,7 +1412,9 @@ void SYCLIntegrationHeader::emitFwdDecl(raw_ostream &O, const Decl *D) {
       break;
     }
     ++NamespaceCnt;
-    NSStr.insert(0, Twine("namespace " + Twine(NS->getName()) + " { ").str());
+    const StringRef NSInlinePrefix = NS->isInline() ? "inline " : "";
+    NSStr.insert(
+        0, Twine(NSInlinePrefix + "namespace " + NS->getName() + " { ").str());
     DC = NS->getDeclContext();
   }
   O << NSStr;

clang/test/CodeGenSYCL/int_header_inline_ns.cpp

@@ -0,0 +1,73 @@
+// RUN: %clang -I %S/Inputs --sycl -Xclang -fsycl-int-header=%t.h %s -c -o kernel.spv
+// RUN: FileCheck -input-file=%t.h %s
+
+// This test checks if the SYCL device compiler is able to generate correct
+// integration header when the kernel name class is wrapped in an inline
+// namespace.
+
+#include "sycl.hpp"
+
+template <typename KernelName, typename KernelType>
+__attribute__((sycl_kernel)) void kernel_single_task(KernelType kernelFunc) {
+  kernelFunc();
+}
+
+// Top-level inline namespace
+// CHECK: inline namespace ns1 {
+// CHECK-NEXT: class Foo11;
+// CHECK-NEXT: }
+// CHECK-NEXT: inline namespace ns1 {
+// CHECK-NEXT: class Foo12;
+// CHECK-NEXT: }
+// CHECK-NEXT: inline namespace ns1 {
+// CHECK-NEXT: class Foo13;
+// CHECK-NEXT: }
+inline namespace ns1 {
+class Foo11 {};
+class Foo12;
+class Foo13 {};
+} // namespace ns1
+
+// Nested inline namespace
+// CHECK-NEXT: namespace ns2 { inline namespace ns3 {
+// CHECK-NEXT: class Foo21;
+// CHECK-NEXT: }}
+// CHECK-NEXT: namespace ns2 { inline namespace ns3 {
+// CHECK-NEXT: class Foo22;
+// CHECK-NEXT: }}
+namespace ns2 {
+inline namespace ns3 {
+class Foo21 {};
+class Foo22;
+} // namespace ns3
+} // namespace ns2
+
+// Namespace nested inside nested inline namespace
+// CHECK-NEXT: namespace ns4 { inline namespace ns5 { namespace ns6 {
+// CHECK-NEXT: class Foo31;
+// CHECK-NEXT: }}}
+// CHECK-NEXT: namespace ns4 { inline namespace ns5 { namespace ns6 {
+// CHECK-NEXT: class Foo32;
+// CHECK-NEXT: }}}
+namespace ns4 {
+inline namespace ns5 {
+namespace ns6 {
+class Foo31 {};
+class Foo32;
+} // namespace ns6
+} // namespace ns5
+} // namespace ns4
+
+int main() {
+  kernel_single_task<Foo11>([]() {});
+  kernel_single_task<::Foo12>([]() {});
+  kernel_single_task<ns1::Foo13>([]() {});
+
+  kernel_single_task<ns2::Foo21>([]() {});
+  kernel_single_task<ns2::ns3::Foo22>([]() {});
+
+  kernel_single_task<ns4::ns6::Foo31>([]() {});
+  kernel_single_task<ns4::ns5::ns6::Foo32>([]() {});
+
+  return 0;
+}