[clang] [clang][diagnostics] Refactor "warn_doc_function_method_decl_mismatch" to use enum_select (PR #146426)

[Erich Keane via cfe-commits]

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@@ -100,32 +100,33 @@ void Sema::checkFunctionDeclVerbatimLine(const BlockCommandComment *Comment) {
   if (!Info->IsFunctionDeclarationCommand)
     return;
 
-  unsigned DiagSelect;
+  std::optional<unsigned> DiagSelect;
   switch (Comment->getCommandID()) {
     case CommandTraits::KCI_function:
-      DiagSelect = (!isAnyFunctionDecl() && !isFunctionTemplateDecl())? 1 : 0;
+      if (!isAnyFunctionDecl() && !isFunctionTemplateDecl())
+        DiagSelect = diag::CallableKind::Function;
       break;
     case CommandTraits::KCI_functiongroup:
-      DiagSelect = (!isAnyFunctionDecl() && !isFunctionTemplateDecl())? 2 : 0;
+      if (!isAnyFunctionDecl() && !isFunctionTemplateDecl())
+        DiagSelect = diag::CallableKind::FunctionGroup;
       break;
     case CommandTraits::KCI_method:
-      DiagSelect = !isObjCMethodDecl() ? 3 : 0;
+      DiagSelect = diag::CallableKind::Method;
       break;
     case CommandTraits::KCI_methodgroup:
-      DiagSelect = !isObjCMethodDecl() ? 4 : 0;
+      DiagSelect = diag::CallableKind::MethodGroup;
       break;
     case CommandTraits::KCI_callback:
-      DiagSelect = !isFunctionPointerVarDecl() ? 5 : 0;
+      DiagSelect = diag::CallableKind::Callback;
       break;
     default:
-      DiagSelect = 0;
+      DiagSelect = std::nullopt;
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erichkeane wrote:

I'd rather just omit the 'default' here.  Default ctor should handle the nullopt construction.

https://github.com/llvm/llvm-project/pull/146426