[clang-tools-extra] [clang-tidy][NFC] Add helper for deprecated check aliases (PR #189522)

[Baranov Victor via cfe-commits]

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@@ -0,0 +1,19 @@
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_CHECKUTILS_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_CHECKUTILS_H
+
+#include "../ClangTidyDiagnosticConsumer.h"
+
+namespace clang::tidy::utils {
+
+/// Returns true when a check is running under a deprecated name and the user
+/// should be prompted to migrate to CanonicalName.
+inline bool isDeprecatedAlias(const ClangTidyContext &Context,
+                              StringRef DeprecatedName,
+                              StringRef CanonicalName) {
+  return Context.isCheckEnabled(DeprecatedName) &&
+         !Context.isCheckEnabled(CanonicalName);
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vbvictor wrote:

On second thought, can we instead pass `diag()` object here and make diagnostic as well?
So we don't have to duplicate `if(..) diag("you have deprecated..")`.
I suspect we wouldn't be able to test it in UnitTests


https://github.com/llvm/llvm-project/pull/189522