[SYCL] Annotate virtual calls in device IR

clang/lib/CodeGen/CGCall.cpp

@@ -5713,6 +5713,14 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   // Apply some call-site-specific attributes.
   // TODO: work this into building the attribute set.
 
+  if (getContext().getLangOpts().SYCLIsDevice && Callee.isVirtual()) {
+    // Annotate virtual calls in SYCL device code to help passes that emit
+    // diagnostics on incorrect uses of virtual functions.
+    Attrs = Attrs.addFnAttribute(
+        getLLVMContext(),
+        llvm::Attribute::get(getLLVMContext(), "virtual-call"));
+  }
+
   // Apply always_inline to all calls within flatten functions.
   // FIXME: should this really take priority over __try, below?
   if (CurCodeDecl && CurCodeDecl->hasAttr<FlattenAttr>() &&

clang/test/CodeGenSYCL/attrs-on-virtual-calls.cpp

@@ -0,0 +1,42 @@
+// Test verifies that clang codegen properly adds call site attributes to
+// device code
+
+// RUN: %clang_cc1 -triple spir64 -fsycl-allow-virtual-functions \
+// RUN:    -fsycl-is-device -emit-llvm %s -o %t.device
+// RUN: FileCheck %s --input-file=%t.device --check-prefixes=CHECK,CHECK-DEVICE
+// RUN: %clang_cc1 -triple x86_64 -fsycl-allow-virtual-functions \
+// RUN:    -fsycl-is-host -emit-llvm %s -o %t.host
+// RUN: FileCheck %s --input-file=%t.host --check-prefixes=CHECK,CHECK-HOST
+
+// CHECK-LABEL: define {{.*}} @_Z4testv
+// CHECK: call{{.*}}void %[[#]](ptr
+// CHECK-DEVICE-SAME: #[[#ATTRS:]]
+// CHECK-HOST-SAME: %[[#]]){{[[:space:]]}}
+// CHECK-DEVICE: attributes #[[#ATTRS]] = {{.*}} "virtual-call"
+
+#ifndef SYCL_EXTERNAL
+#define SYCL_EXTERNAL
+#endif
+
+SYCL_EXTERNAL bool rand();
+
+class Base {
+public:
+  [[__sycl_detail__::add_ir_attributes_function("indirectly-callable", "")]]
+  virtual void display() {}
+};
+
+class Derived1 : public Base {
+public:
+  [[__sycl_detail__::add_ir_attributes_function("indirectly-callable", "")]]
+  void display() override {}
+};
+
+SYCL_EXTERNAL void test() {
+  Derived1 d1;
+  Base *b = nullptr;
+  if (rand())
+    b = &d1;
+  b->display();
+}
+