clang-tidy: add check for non-trivial thread_local vars

Do not allow thread_local vars with non-trivial destructors

contrib/devtools/bitcoin-tidy/nontrivial-threadlocal.cpp

@@ -0,0 +1,44 @@
+// Copyright (c) 2023 Bitcoin Developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "nontrivial-threadlocal.h"
+
+#include <clang/AST/ASTContext.h>
+#include <clang/ASTMatchers/ASTMatchFinder.h>
+
+
+// Copied from clang-tidy's UnusedRaiiCheck
+namespace {
+AST_MATCHER(clang::CXXRecordDecl, hasNonTrivialDestructor) {
+    // TODO: If the dtor is there but empty we don't want to warn either.
+    return Node.hasDefinition() && Node.hasNonTrivialDestructor();
+}
+} // namespace
+
+namespace bitcoin {
+
+void NonTrivialThreadLocal::registerMatchers(clang::ast_matchers::MatchFinder* finder)
+{
+    using namespace clang::ast_matchers;
+
+    /*
+      thread_local std::string foo;
+    */
+
+    finder->addMatcher(
+        varDecl(
+            hasThreadStorageDuration(),
+            hasType(hasCanonicalType(recordType(hasDeclaration(cxxRecordDecl(hasNonTrivialDestructor())))))
+        ).bind("nontrivial_threadlocal"),
+        this);
+}
+
+void NonTrivialThreadLocal::check(const clang::ast_matchers::MatchFinder::MatchResult& Result)
+{
+    if (const clang::VarDecl* var = Result.Nodes.getNodeAs<clang::VarDecl>("nontrivial_threadlocal")) {
+        const auto user_diag = diag(var->getBeginLoc(), "Variable with non-trivial destructor cannot be thread_local.");
+    }
+}
+
+} // namespace bitcoin