[clang] [clang] Fix inconsistencies with the device_kernel attr on different targets (PR #161905)

[Joseph Huber via cfe-commits]

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@@ -5204,25 +5204,55 @@ static void handleCallConvAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
 static void handleDeviceKernelAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
   const auto *FD = dyn_cast_or_null<FunctionDecl>(D);
   bool IsFunctionTemplate = FD && FD->getDescribedFunctionTemplate();
-  if (S.getLangOpts().SYCLIsDevice) {
+  llvm::Triple Triple = S.getASTContext().getTargetInfo().getTriple();
+  const LangOptions &LangOpts = S.getLangOpts();
+
+  if (LangOpts.SYCLIsDevice) {
     if (!IsFunctionTemplate) {
       S.Diag(AL.getLoc(), diag::warn_attribute_wrong_decl_type_str)
           << AL << AL.isRegularKeywordAttribute() << "function templates";
+      AL.setInvalid();
+      return;
     } else {
       S.SYCL().handleKernelAttr(D, AL);
     }
   } else if (DeviceKernelAttr::isSYCLSpelling(AL)) {
     S.Diag(AL.getLoc(), diag::warn_attribute_ignored) << AL;
-  } else if (S.getASTContext().getTargetInfo().getTriple().isNVPTX()) {
+    AL.setInvalid();
+
+    return;
+  } else if (Triple.isNVPTX()) {
     handleGlobalAttr(S, D, AL);
   } else {
     // OpenCL C++ will throw a more specific error.
-    if (!S.getLangOpts().OpenCLCPlusPlus && (!FD || IsFunctionTemplate)) {
+    if (!LangOpts.OpenCLCPlusPlus && (!FD || IsFunctionTemplate)) {
       S.Diag(AL.getLoc(), diag::err_attribute_wrong_decl_type_str)
           << AL << AL.isRegularKeywordAttribute() << "functions";
+      AL.setInvalid();
+      return;
     }
     handleSimpleAttribute<DeviceKernelAttr>(S, D, AL);
   }
+  // TODO: isGPU() should probably return true for SPIR.
+  bool TargetDeviceEnvironment = Triple.isGPU() || Triple.isSPIR() ||
+                                 LangOpts.isTargetDevice() || LangOpts.OpenCL;
+  bool IsAMDGPUMismatch =
+      DeviceKernelAttr::isAMDGPUSpelling(AL) && !Triple.isAMDGPU();
+  bool IsNVPTXMismatch =
+      DeviceKernelAttr::isNVPTXSpelling(AL) && !Triple.isNVPTX();
+  if (IsAMDGPUMismatch || IsNVPTXMismatch || !TargetDeviceEnvironment) {
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jhuber6 wrote:

Honestly I'm wondering what we should do here. Realistically it would make sense for these 'named' attributes to just be legacy aliases to `device_kernel`. I don't see any real value in keeping separate names unless there are special semantics that I'm unaware of. Ever since PTX moved over, this attribute is more plainly "set the kernel calling convention on this function."

https://github.com/llvm/llvm-project/pull/161905