Adding upstream version 1:7.0.4.upstream/1%7.0.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 167 insertions, 0 deletions

diff --git a/compilerplugins/clang/weakobject.cxx b/compilerplugins/clang/weakobject.cxx
new file mode 100644
index 000000000..afa652bef
--- /dev/null
+++ b/compilerplugins/clang/weakobject.cxx
@@ -0,0 +1,167 @@
+/* -*- 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/.
+ */
+
+#ifndef LO_CLANG_SHARED_PLUGINS
+
+#include "check.hxx"
+#include "plugin.hxx"
+
+/* OWeakObject::release() disposes weak references.  If that isn't done
+ * because a sub-class improperly overrides release() then
+ * OWeakConnectionPoint::m_pObject continues to point to the deleted object
+ * and that could result in use-after-free.
+ */
+
+namespace {
+
+class WeakObject
+    : public loplugin::FilteringPlugin<WeakObject>
+{
+
+public:
+    explicit WeakObject(loplugin::InstantiationData const& rData): FilteringPlugin(rData)
+    {}
+
+    virtual bool preRun() override {
+        return compiler.getLangOpts().CPlusPlus; // no OWeakObject in C
+    }
+    void run() override {
+        if( preRun()) {
+            TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+        }
+    }
+
+    bool isDerivedFromOWeakObject(CXXMethodDecl const*const pMethodDecl)
+    {
+        QualType const pClass(pMethodDecl->getParent()->getTypeForDecl(), 0);
+        if (loplugin::TypeCheck(pClass).Class("OWeakObject").Namespace("cppu"))
+        {
+            return true;
+        }
+        // hopefully it's faster to recurse overridden methods than the
+        // thicket of WeakImplHelper32 but that is purely speculation
+        for (auto it = pMethodDecl->begin_overridden_methods();
+             it != pMethodDecl->end_overridden_methods(); ++it)
+        {
+            if (isDerivedFromOWeakObject(*it))
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    bool VisitCXXMethodDecl(CXXMethodDecl const*const pMethodDecl)
+    {
+        if (ignoreLocation(pMethodDecl)) {
+            return true;
+        }
+        if (!pMethodDecl->isThisDeclarationADefinition()
+            || pMethodDecl->isLateTemplateParsed())
+        {
+            return true;
+        }
+        if (!pMethodDecl->isInstance()) {
+            return true;
+        }
+// this is too "simple", if a NamedDecl class has a getName() member expecting it to actually work would clearly be unreasonable    if (pMethodDecl->getName() != "release") {
+        if (auto const i = pMethodDecl->getIdentifier()) {
+            if (i != nullptr && !i->isStr("release")) {
+                return true;
+            }
+        }
+        if (pMethodDecl->getNumParams() != 0) {
+            return true;
+        }
+        if (loplugin::TypeCheck(QualType(pMethodDecl->getParent()->getTypeForDecl(), 0)).Class("OWeakObject").Namespace("cppu"))
+        {
+            return true;
+        }
+
+        CXXMethodDecl const* pOverridden(nullptr);
+        for (auto it = pMethodDecl->begin_overridden_methods();
+             it != pMethodDecl->end_overridden_methods(); ++it)
+        {
+            if (auto const i = (*it)->getIdentifier()) {
+                if (i != nullptr && i->isStr("release")) {
+                    pOverridden = *it;
+                    break;
+                }
+            }
+        }
+        if (pOverridden == nullptr)
+        {
+            return true;
+        }
+        if (!isDerivedFromOWeakObject(pOverridden))
+        {
+            return true;
+        }
+        CompoundStmt const*const pCompoundStatement(
+                dyn_cast<CompoundStmt>(pMethodDecl->getBody()));
+        for (auto i = pCompoundStatement->body_begin();
+             i != pCompoundStatement->body_end(); ++i)
+        {
+            // note: this is not a CXXMemberCallExpr
+            CallExpr const*const pCallExpr(dyn_cast<CallExpr>(*i));
+            if (pCallExpr)
+            {
+                // note: this is only sometimes a CXXMethodDecl
+                FunctionDecl const*const pCalled(pCallExpr->getDirectCallee());
+                if (pCalled->getName() == "release")
+                {
+//this never works  && pCalled == pOverridden
+                    if (pCalled->getParent() == pOverridden->getParent())
+                    {
+                        return true;
+                    }
+                    // Allow this convenient shortcut:
+                    auto td = dyn_cast<TypeDecl>(pCalled->getParent());
+                    if (td != nullptr
+                        && (loplugin::TypeCheck(td).Class("OWeakObject").Namespace("cppu").GlobalNamespace()
+                            || loplugin::TypeCheck(td).Class("OWeakAggObject").Namespace("cppu").GlobalNamespace()))
+                    {
+                        return true;
+                    }
+                }
+            }
+        }
+
+        // whitelist
+        auto tc  = loplugin::TypeCheck(pMethodDecl->getParent());
+        if (   tc.Class("OWeakAggObject").Namespace("cppu").GlobalNamespace() // conditional call
+            || tc.Class("WeakComponentImplHelperBase").Namespace("cppu").GlobalNamespace() // extra magic
+            || tc.Class("WeakAggComponentImplHelperBase").Namespace("cppu").GlobalNamespace() // extra magic
+            || tc.Class("CDOMImplementation").Namespace("DOM").GlobalNamespace() // a static oddity
+            || tc.Class("SwXTextFrame").GlobalNamespace() // ambiguous, 3 parents
+            || tc.Class("SwXTextDocument").GlobalNamespace() // ambiguous, ~4 parents
+            || tc.Class("SdStyleSheet").GlobalNamespace() // same extra magic as WeakComponentImplHelperBase
+            || tc.Class("SdXImpressDocument").GlobalNamespace() // same extra magic as WeakComponentImplHelperBase
+           )
+        {
+            return true;
+        }
+
+        report(DiagnosticsEngine::Warning,
+                "override of OWeakObject::release() does not call superclass release()",
+                pMethodDecl->getLocation())
+            << pMethodDecl->getSourceRange();
+
+        return true;
+    }
+
+};
+
+loplugin::Plugin::Registration<WeakObject> weakobject("weakobject");
+
+} // namespace
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */