[clang-tools-extra] [clang-tidy] Portability Template Virtual Member Function Check (PR #110099)

[via cfe-commits]

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@@ -0,0 +1,48 @@
+//===--- TemplateVirtualMemberFunctionCheck.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 "TemplateVirtualMemberFunctionCheck.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::portability {
+
+void TemplateVirtualMemberFunctionCheck::registerMatchers(MatchFinder *Finder) {
+  Finder->addMatcher(classTemplateSpecializationDecl().bind("specialization"),
+                     this);
+}
+
+void TemplateVirtualMemberFunctionCheck::check(
+    const MatchFinder::MatchResult &Result) {
+  const auto *MatchedDecl =
+      Result.Nodes.getNodeAs<ClassTemplateSpecializationDecl>("specialization");
+
+  if (MatchedDecl->isExplicitSpecialization())
+    return;
----------------
isuckatcs wrote:

In this case there is an implicit instantiation, which results in the `ClassTemplateSpecializationDecl <line:9:1, line:14:1> line:10:8 struct CrossPlatformError definition implicit_instantiation` node. If you delete the `CrossPlatformError<int>::used();` line, the error is not reported even though the partial specialization is present.

This case is detected by the current implementation, I also added a testcase about it recently.

https://github.com/llvm/llvm-project/pull/110099