[clang] [SYCL] Basic code generation for SYCL kernel caller offload entry point functions. (PR #133030)

[Mariya Podchishchaeva via cfe-commits]

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@@ -3303,6 +3303,27 @@ void CodeGenModule::EmitDeferred() {
   CurDeclsToEmit.swap(DeferredDeclsToEmit);
 
   for (GlobalDecl &D : CurDeclsToEmit) {
+    // Functions declared with the sycl_kernel_entry_point attribute are
+    // emitted normally during host compilation. During device compilation,
+    // a SYCL kernel caller offload entry point function is generated and
+    // emitted in place of each of these functions.
+    if (const auto *FD = D.getDecl()->getAsFunction()) {
+      if (LangOpts.SYCLIsDevice && FD->hasAttr<SYCLKernelEntryPointAttr>() &&
+          FD->isDefined()) {
+        // Functions with an invalid sycl_kernel_entry_point attribute are
+        // ignored during device compilation.
+        if (!FD->getAttr<SYCLKernelEntryPointAttr>()->isInvalidAttr()) {
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Fznamznon wrote:

Can we simply drop the attribute if it is invalid when checking its validity? 

https://github.com/llvm/llvm-project/pull/133030