[SYCL] Fix memory access inside deallocated region when using default accessor (#20632)

This PR addresses the root cause behind #20423. When an accessor that
has not been constructed with a `handler` instance is passed to the
`set_args` function of a `handler` such as a default accessor, the
lifetime of its dynamically allocated resources can potentially be
shorter than the lifetime of the `handler` itself which causes problems,
for instance, in the `finalize` function of the `handler` where we may
end up accessing freed memory.

Author: lbushi25

sycl/include/sycl/handler.hpp

@@ -679,6 +679,8 @@ class __SYCL_EXPORT handler {
       accessor<DataT, Dims, AccessMode, AccessTarget, IsPlaceholder> &&Arg) {
     detail::AccessorBaseHost *AccBase = (detail::AccessorBaseHost *)&Arg;
     const detail::AccessorImplPtr &AccImpl = detail::getSyclObjImpl(*AccBase);
+    // Ensure the data of AccImpl lives at least as long as the handler.
+    addLifetimeSharedPtrStorage(AccImpl);
     detail::AccessorImplHost *Req = AccImpl.get();
     // Add accessor to the list of arguments.
     addArg(detail::kernel_param_kind_t::kind_accessor, Req,

sycl/test-e2e/FreeFunctionKernels/enum_parameter.cpp

@@ -39,26 +39,26 @@ int main() {
 
   bool flag1, flag2, flag3;
   flag1 = (flag2 = (flag3 = false));
-  rAccType acc1;
-  wAccType acc2;
-  rwAccType acc3;
   {
     sycl::buffer<bool, 1> flagBuffer1(&flag1, 1);
     sycl::buffer<bool, 1> flagBuffer2(&flag2, 1);
     sycl::buffer<bool, 1> flagBuffer3(&flag3, 1);
     Queue.submit([&](sycl::handler &Handler) {
+      rAccType acc1;
       flagType flagAcc1{flagBuffer1, Handler};
       Handler.set_args(acc1, rMode, flagAcc1);
       Handler.single_task(Kernel1);
     });
 
     Queue.submit([&](sycl::handler &Handler) {
+      wAccType acc2;
       flagType flagAcc2{flagBuffer2, Handler};
       Handler.set_args(acc2, wMode, flagAcc2);
       Handler.single_task(Kernel2);
     });
 
     Queue.submit([&](sycl::handler &Handler) {
+      rwAccType acc3;
       flagType flagAcc3{flagBuffer3, Handler};
       Handler.set_args(acc3, rwMode, flagAcc3);
       Handler.single_task(Kernel3);