[clang] [OpenACC] Implement Atomic construct variants (PR #73015)

[Alexey Bataev via cfe-commits]

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@@ -59,9 +60,21 @@ OpenACCDirectiveKindEx getOpenACCDirectiveKind(StringRef Name) {
   return llvm::StringSwitch<OpenACCDirectiveKindEx>(Name)
       .Case("enter", OpenACCDirectiveKindEx::Enter)
       .Case("exit", OpenACCDirectiveKindEx::Exit)
+      .Case("atomic", OpenACCDirectiveKindEx::Atomic)
       .Default(OpenACCDirectiveKindEx::Invalid);
 }
 
+// Since 'atomic' is effectively a compound directive, this will decode the
+// second part of the directive.
+OpenACCDirectiveKind getOpenACCAtomicDirectiveKind(StringRef Name) {
+  return llvm::StringSwitch<OpenACCDirectiveKind>(Name)
+      .Case("read", OpenACCDirectiveKind::AtomicRead)
+      .Case("write", OpenACCDirectiveKind::AtomicWrite)
+      .Case("update", OpenACCDirectiveKind::AtomicUpdate)
+      .Case("capture", OpenACCDirectiveKind::AtomicCapture)
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alexey-bataev wrote:

I think this may cause problems in future, if new combinations of clauses will appear. It will be very hard to redesign it to represent the new clauses as directives-kind (especially if the new clauses will support non-strict use order).

https://github.com/llvm/llvm-project/pull/73015