new loplugin:xmlimport

to help me maintain the invariants when updating code to use the
FastParser APIs. One weird invariant is that you need to override
startFastElement or the createFastChildContext will not get called.

Not all of these changes are probably necessary - some of the classes
are never constructured themselves, only their subclasses are
constructed, and their subclasses maintain the invariants, but it is
just easier to scatter a few more startFastElement around

Change-Id: I3f70fb5a1e44c311cf4926fa7b0fcda605709eac
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89473
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

2 files changed, 193 insertions, 0 deletions

diff --git a/compilerplugins/clang/test/xmlimport.cxx b/compilerplugins/clang/test/xmlimport.cxx
new file mode 100644
index 000000000000..965d4936e41c
--- /dev/null
+++ b/compilerplugins/clang/test/xmlimport.cxx
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * 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 "sal/config.h"
+
+// Cannot include this, makes clang crash
+//#include "xmloff/xmlimp.hxx"
+
+class SvXMLImportContext
+{
+public:
+    virtual ~SvXMLImportContext() {}
+
+    virtual void createFastChildContext() {}
+    virtual void startFastElement() {}
+    virtual void endFastElement() {}
+};
+
+class Test1 : public SvXMLImportContext
+{
+public:
+    // expected-error@+1 {{must override startFastElement too [loplugin:xmlimport]}}
+    virtual void createFastChildContext() override;
+};
+
+class Test2 : public SvXMLImportContext
+{
+public:
+    // no warning expected
+    virtual void createFastChildContext() override;
+    virtual void startFastElement() override {}
+};
+
+class Test3 : public Test2
+{
+public:
+    // no warning expected
+    virtual void createFastChildContext() override;
+};
+
+class Test4 : public SvXMLImportContext
+{
+public:
+    // expected-error@+1 {{must override startFastElement too [loplugin:xmlimport]}}
+    virtual void endFastElement() override;
+};
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/compilerplugins/clang/xmlimport.cxx b/compilerplugins/clang/xmlimport.cxx
new file mode 100644
index 000000000000..bdb41f616859
--- /dev/null
+++ b/compilerplugins/clang/xmlimport.cxx
@@ -0,0 +1,139 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * Based on LLVM/Clang.
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ */
+#ifndef LO_CLANG_SHARED_PLUGINS
+
+#include "compat.hxx"
+#include "plugin.hxx"
+#include "check.hxx"
+#include <iostream>
+#include "clang/AST/CXXInheritance.h"
+
+/*
+ * This is a compile-time checker.
+ *
+ * Check that when we override SvXmlImportContext, and we override createFastChildContext,
+ * we have also overridden startFastElement, or the fast-parser stuff will not work
+ * correctly.
+*/
+
+namespace
+{
+class XmlImport : public loplugin::FilteringPlugin<XmlImport>
+{
+public:
+    explicit XmlImport(loplugin::InstantiationData const& data)
+        : FilteringPlugin(data)
+    {
+    }
+
+    bool preRun() override
+    {
+        //        std::string fn(handler.getMainFileName());
+        //        loplugin::normalizeDotDotInFilePath(fn);
+        return true;
+    }
+
+    void run() override
+    {
+        if (preRun())
+        {
+            TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+        }
+    }
+
+    bool VisitCXXMethodDecl(const CXXMethodDecl*);
+};
+
+static bool containsStartFastElementMethod(const CXXRecordDecl* cxxRecordDecl,
+                                           bool& rbFoundImportContext)
+{
+    auto dc = loplugin::DeclCheck(cxxRecordDecl);
+    if (dc.Class("SvXMLImportContext"))
+    {
+        rbFoundImportContext = true;
+        return false;
+    }
+    if (dc.Class("XFastContextHandler"))
+        return false;
+    for (auto it = cxxRecordDecl->method_begin(); it != cxxRecordDecl->method_end(); ++it)
+    {
+        auto i = *it;
+        if (i->getIdentifier() && i->getName() == "startFastElement")
+        {
+            //            i->dump();
+            return true;
+        }
+    }
+    return false;
+}
+bool XmlImport::VisitCXXMethodDecl(const CXXMethodDecl* methodDecl)
+{
+    auto beginLoc = compat::getBeginLoc(methodDecl);
+    if (!beginLoc.isValid() || ignoreLocation(beginLoc))
+        return true;
+
+    auto cxxRecordDecl = methodDecl->getParent();
+    if (!cxxRecordDecl || !cxxRecordDecl->getIdentifier())
+        return true;
+    auto className = cxxRecordDecl->getName();
+    if (className == "OOXMLFactory") // writerfilter
+        return true;
+    if (className == "SvXMLLegacyToFastDocHandler" || className == "ImportDocumentHandler"
+        || className == "ExportDocumentHandler") // reportdesign
+        return true;
+    if (className == "XMLEmbeddedObjectExportFilter" || className == "XMLBasicExportFilter"
+        || className == "XMLTransformerBase" || className == "SvXMLMetaExport") // xmloff
+        return true;
+    if (!methodDecl->getIdentifier())
+        return true;
+    if (!(methodDecl->getName() == "createFastChildContext" || methodDecl->getName() == "characters"
+          || methodDecl->getName() == "endFastElement"))
+        return true;
+    if (loplugin::DeclCheck(cxxRecordDecl).Class("SvXMLImportContext"))
+        return true;
+
+    bool foundImportContext = false;
+    if (containsStartFastElementMethod(cxxRecordDecl, foundImportContext))
+        return true;
+
+    bool foundStartFastElement = false;
+    CXXBasePaths aPaths;
+    cxxRecordDecl->lookupInBases(
+        [&](const CXXBaseSpecifier* Specifier, CXXBasePath & /*Path*/) -> bool {
+            if (!Specifier->getType().getTypePtr())
+                return false;
+            const CXXRecordDecl* baseCXXRecordDecl = Specifier->getType()->getAsCXXRecordDecl();
+            if (!baseCXXRecordDecl)
+                return false;
+            if (baseCXXRecordDecl->isInvalidDecl())
+                return false;
+            foundStartFastElement
+                |= containsStartFastElementMethod(baseCXXRecordDecl, foundImportContext);
+            return false;
+        },
+        aPaths);
+
+    if (foundStartFastElement || !foundImportContext)
+        return true;
+
+    report(DiagnosticsEngine::Warning, "must override startFastElement too",
+           compat::getBeginLoc(methodDecl))
+        << methodDecl->getSourceRange();
+    return true;
+}
+
+loplugin::Plugin::Registration<XmlImport> xmlimport("xmlimport");
+
+} // namespace
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */