new loplugin fragiledestructor

fix up a small number of places that it finds

Change-Id: Iedc91e141edfb28f727454f698cd2155a7fd5bf4
Reviewed-on: https://gerrit.libreoffice.org/26566
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noelgrandin@gmail.com>

1 files changed, 113 insertions, 0 deletions

diff --git a/compilerplugins/clang/fragiledestructor.cxx b/compilerplugins/clang/fragiledestructor.cxx
new file mode 100644
index 000000000000..ebce1d677f8b
--- /dev/null
+++ b/compilerplugins/clang/fragiledestructor.cxx
@@ -0,0 +1,113 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <string>
+#include <iostream>
+
+#include "plugin.hxx"
+#include "compat.hxx"
+#include "clang/AST/CXXInheritance.h"
+
+
+// Check for calls to virtual methods from destructors. These are dangerous because intention might be to call
+// a method on a subclass, while in actual fact, it only calls the method on the current or super class.
+//
+
+namespace {
+
+class FragileDestructor:
+    public RecursiveASTVisitor<FragileDestructor>, public loplugin::Plugin
+{
+public:
+    explicit FragileDestructor(InstantiationData const & data): Plugin(data) {}
+
+    virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
+
+    bool VisitCXXDestructorDecl(const CXXDestructorDecl *);
+
+    bool VisitCXXMemberCallExpr(const CXXMemberCallExpr *);
+
+private:
+    bool mbChecking = false;
+};
+
+bool FragileDestructor::VisitCXXDestructorDecl(const CXXDestructorDecl* pCXXDestructorDecl)
+{
+    if (ignoreLocation(pCXXDestructorDecl)) {
+        return true;
+    }
+    if (!pCXXDestructorDecl->isThisDeclarationADefinition()) {
+        return true;
+    }
+    // ignore this for now, too tricky for me to work out
+    StringRef aFileName = compiler.getSourceManager().getFilename(
+            compiler.getSourceManager().getSpellingLoc(pCXXDestructorDecl->getLocStart()));
+    if (aFileName.startswith(SRCDIR "/include/comphelper/")
+        || aFileName.startswith(SRCDIR "/include/cppuhelper/")
+        || aFileName.startswith(SRCDIR "/cppuhelper/")
+        || aFileName.startswith(SRCDIR "/comphelper/")
+        // dont know how to detect this in clang - it is making an explicit call to it's own method, so presumably OK
+        || aFileName == SRCDIR "/basic/source/sbx/sbxvalue.cxx"
+       )
+        return true;
+    mbChecking = true;
+    Stmt * pStmt = pCXXDestructorDecl->getBody();
+    TraverseStmt(pStmt);
+    mbChecking = false;
+    return true;
+}
+
+bool FragileDestructor::VisitCXXMemberCallExpr(const CXXMemberCallExpr* callExpr)
+{
+    if (!mbChecking || ignoreLocation(callExpr)) {
+        return true;
+    }
+    const CXXMethodDecl* methodDecl = callExpr->getMethodDecl();
+    if (!methodDecl->isVirtual() || methodDecl->hasAttr<FinalAttr>()) {
+        return true;
+    }
+    const CXXRecordDecl* parentRecordDecl = methodDecl->getParent();
+    if (parentRecordDecl->hasAttr<FinalAttr>()) {
+        return true;
+    }
+    if (!callExpr->getImplicitObjectArgument()->IgnoreImpCasts()->isImplicitCXXThis()) {
+        return true;
+    }
+    // if we see an explicit call to it's own method, thats OK
+    auto s1 = compiler.getSourceManager().getCharacterData(callExpr->getLocStart());
+    auto s2 = compiler.getSourceManager().getCharacterData(callExpr->getLocEnd());
+    std::string tok(s1, s2-s1);
+    if (tok.find("::") != std::string::npos) {
+        return true;
+    }
+    // e.g. osl/thread.hxx and cppuhelper/compbase.hxx
+    StringRef aFileName = compiler.getSourceManager().getFilename(compiler.getSourceManager().getSpellingLoc(methodDecl->getLocStart()));
+    if (aFileName.startswith(SRCDIR "/include/osl/")
+        || aFileName.startswith(SRCDIR "/include/comphelper/")
+        || aFileName.startswith(SRCDIR "/include/cppuhelper/"))
+        return true;
+    report(
+        DiagnosticsEngine::Warning,
+        "calling virtual method from destructor, either make the virtual method SAL_FINAL, or make this class SAL_FINAL",
+        callExpr->getLocStart())
+      << callExpr->getSourceRange();
+    report(
+        DiagnosticsEngine::Note,
+        "callee method here",
+        methodDecl->getLocStart())
+      << methodDecl->getSourceRange();
+    return true;
+}
+
+
+loplugin::Plugin::Registration< FragileDestructor > X("fragiledestructor", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */