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

[Tom Honermann via cfe-commits]

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@@ -387,8 +397,162 @@ void SemaSYCL::CheckSYCLEntryPointFunctionDecl(FunctionDecl *FD) {
   }
 }
 
+ExprResult SemaSYCL::BuildSYCLKernelLaunchIdExpr(FunctionDecl *FD,
+                                                 QualType KNT) {
+  // The current context must be the function definition context to ensure
+  // that name lookup is performed within the correct scope.
+  assert(SemaRef.CurContext == FD);
+
+  // An appropriate source location is required to emit diagnostics if
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tahonermann wrote:

I did come across one case where a source location was being passed to indicate the presence of a `template` keyword used as a disambiguator. In that case, passing a source location resulted in a spurious diagnostic (see [here](https://github.com/llvm/llvm-project/blob/4abaf068067c7870005c29a09f2be991a156ed3e/clang/test/SemaSYCL/sycl-host-kernel-launch.cpp#L23)). I addressed this by (intentionally) passing an invalid source location since the synthesized call expression has no need to reflect use of `template` as a disambiguator.

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