[clang] [SYCL] SYCL host kernel launch support for the sycl_kernel_entry_point attribute. (PR #152403)

[Mariya Podchishchaeva via cfe-commits]

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@@ -683,24 +696,55 @@ There are a few items worthy of note:
    or more parameters depending on how the SYCL library implementation defines
    these types.
 
-#. The call to ``kernel_entry_point()`` has no effect other than to trigger
-   emission of the entry point function. The statments that make up the body
-   of the function are not executed when the function is called; they are
-   only used in the generation of the entry point function.
+The call to ``kernel_entry_point()`` by ``single_task()`` is effectively
+replaced with synthesized code that looks approximately as follows.
+
+.. code-block:: c++
+
+  sycl::stream sout = Kernel.sout;
+  S s = Kernel.s;
+  sycl_kernel_launch<KN>("kernel-symbol-name", sout, s);
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Fznamznon wrote:

Why do we require KN template parameter for sycl_kernel_launch? It would be great to have an explanation here because I don't know and I spent some time actually implementing this.

https://github.com/llvm/llvm-project/pull/152403