[clang-tools-extra] [clang-tidy] Add new check bugprone-tagged-union-member-count (PR #89925)

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In-Reply-To: <llvm.org/llvm/llvm-project/pull/89925 at github.com>


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@@ -0,0 +1,214 @@
+//===--- TaggedUnionMemberCountCheck.cpp - clang-tidy ---------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "TaggedUnionMemberCountCheck.h"
+#include "../utils/OptionsUtils.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallSet.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+const char StrictModeOptionName[] = "StrictMode";
+const char EnableCountingEnumHeuristicOptionName[] =
+    "EnableCountingEnumHeuristic";
+const char CountingEnumPrefixesOptionName[] = "CountingEnumPrefixes";
+const char CountingEnumSuffixesOptionName[] = "CountingEnumSuffixes";
+
+TaggedUnionMemberCountCheck::TaggedUnionMemberCountCheck(
+    StringRef Name, ClangTidyContext *Context)
+    : ClangTidyCheck(Name, Context),
+      StrictMode(Options.get(StrictModeOptionName, false)),
+      EnableCountingEnumHeuristic(
+          Options.get(EnableCountingEnumHeuristicOptionName, true)),
+      RawCountingEnumPrefixes(Options.get(CountingEnumPrefixesOptionName, "")),
+      RawCountingEnumSuffixes(
+          Options.get(CountingEnumSuffixesOptionName, "count")),
+      ParsedCountingEnumPrefixes(
+          utils::options::parseStringList(RawCountingEnumPrefixes)),
+      ParsedCountingEnumSuffixes(
+          utils::options::parseStringList(RawCountingEnumSuffixes)),
----------------
whisperity wrote:

Technically what could happen here is that the `class` only stores the parsed list, and `storeOptions()` re-serialises the parsed input back into its raw comma(?)-separated form, there is a corresponding `utils::` function for this.

(The entire `storeOptions()` thing is only needed, AFAIK, for checkers that would inherit yours, anyway. So it's not called often, but would save us having additional data members that do not 1:1 correspond to the configuration (or the intermittent temporary data) meaningfully.) 

https://github.com/llvm/llvm-project/pull/89925