[clang] [clang][SYCL] Add sycl_external attribute and restrict emitting device code (PR #140282)

[via cfe-commits]

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@@ -12910,6 +12910,18 @@ def err_sycl_special_type_num_init_method : Error<
   "types with 'sycl_special_class' attribute must have one and only one '__init' "
   "method defined">;
 
+// SYCL external attribute diagnostics
+def err_sycl_attribute_invalid_linkage : Error<
+  "'clang::sycl_external' can only be applied to functions with external"
+  " linkage">;
+def err_sycl_attribute_invalid_main : Error<
+  "'clang::sycl_external' cannot be applied to the 'main' function">;
+def err_sycl_attribute_invalid_deleted_function : Error<
+  "'clang::sycl_external' cannot be applied to an explicitly deleted function">;
+def warn_attribute_missing_on_first_decl : Warning<
+  "%0 attribute does not appear on the first declaration">,
+  InGroup<IgnoredAttributes>;
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schittir wrote:

Added a "nonportable-sycl" diagnostic group. https://github.com/llvm/llvm-project/pull/140282/commits/a88cf0e4af22815153e6f51dc51d8d9d31212d07

https://github.com/llvm/llvm-project/pull/140282