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-rw-r--r--compilerplugins/clang/unnecessaryvirtual.cxx206
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diff --git a/compilerplugins/clang/unnecessaryvirtual.cxx b/compilerplugins/clang/unnecessaryvirtual.cxx
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+/* -*- 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 <cassert>
+#include <string>
+#include <iostream>
+#include <set>
+#include <unordered_set>
+#include "config_clang.h"
+#include "plugin.hxx"
+#include <fstream>
+
+/**
+Dump a list of virtual methods and a list of methods overriding virtual methods.
+Then we will post-process the 2 lists and find the set of virtual methods which don't need to be virtual.
+
+Also, we look for virtual methods where the bodies of all the overrides are empty i.e. this is leftover code
+that no longer has a purpose.
+
+The process goes something like this:
+ $ make check
+ $ make FORCE_COMPILE=all COMPILER_PLUGIN_TOOL='unnecessaryvirtual' check
+ $ ./compilerplugins/clang/unnecessaryvirtual.py
+ $ for dir in *; do make FORCE_COMPILE=all UPDATE_FILES=$dir COMPILER_PLUGIN_TOOL='removevirtuals' $dir; done
+
+Note that the actual process may involve a fair amount of undoing, hand editing, and general messing around
+to get it to work :-)
+
+TODO some boost bind stuff appears to confuse it, notably in the xmloff module
+*/
+
+namespace {
+
+struct MyFuncInfo
+{
+ std::string name;
+ std::string sourceLocation;
+
+};
+bool operator < (const MyFuncInfo &lhs, const MyFuncInfo &rhs)
+{
+ return lhs.name < rhs.name;
+}
+
+// try to limit the voluminous output a little
+static std::set<MyFuncInfo> definitionSet;
+static std::unordered_set<std::string> overridingSet;
+static std::unordered_set<std::string> nonEmptySet;
+
+class UnnecessaryVirtual:
+ public RecursiveASTVisitor<UnnecessaryVirtual>, public loplugin::Plugin
+{
+public:
+ explicit UnnecessaryVirtual(loplugin::InstantiationData const & data):
+ Plugin(data) {}
+
+ virtual void run() override
+ {
+ TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+
+ // dump all our output in one write call - this is to try and limit IO "crosstalk" between multiple processes
+ // writing to the same logfile
+ std::string output;
+ for (const MyFuncInfo & s : definitionSet)
+ output += "definition:\t" + s.name + "\t" + s.sourceLocation + "\n";
+ for (const std::string & s : overridingSet)
+ output += "overriding:\t" + s + "\n";
+ for (const std::string & s : nonEmptySet)
+ output += "nonempty:\t" + s + "\n";
+ std::ofstream myfile;
+ myfile.open( WORKDIR "/loplugin.unnecessaryvirtual.log", std::ios::app | std::ios::out);
+ myfile << output;
+ myfile.close();
+ }
+ bool shouldVisitTemplateInstantiations () const { return true; }
+ bool shouldVisitImplicitCode() const { return true; }
+
+ bool VisitCXXMethodDecl( const CXXMethodDecl* decl );
+private:
+ void MarkRootOverridesNonEmpty( const CXXMethodDecl* methodDecl );
+ std::string toString(SourceLocation loc);
+};
+
+std::string niceName(const CXXMethodDecl* cxxMethodDecl)
+{
+ while (cxxMethodDecl->getTemplateInstantiationPattern())
+ cxxMethodDecl = dyn_cast<CXXMethodDecl>(cxxMethodDecl->getTemplateInstantiationPattern());
+ while (cxxMethodDecl->getInstantiatedFromMemberFunction())
+ cxxMethodDecl = dyn_cast<CXXMethodDecl>(cxxMethodDecl->getInstantiatedFromMemberFunction());
+ std::string s = cxxMethodDecl->getReturnType().getCanonicalType().getAsString()
+ + " " + cxxMethodDecl->getQualifiedNameAsString() + "(";
+ for (const ParmVarDecl *pParmVarDecl : cxxMethodDecl->parameters()) {
+ s += pParmVarDecl->getType().getCanonicalType().getAsString();
+ s += ",";
+ }
+ s += ")";
+ if (cxxMethodDecl->isConst()) {
+ s += "const";
+ }
+ return s;
+}
+
+bool UnnecessaryVirtual::VisitCXXMethodDecl( const CXXMethodDecl* methodDecl )
+{
+ if (!methodDecl->isVirtual() || methodDecl->isDeleted()) {
+ return true;
+ }
+ // ignore stuff that forms part of the stable URE interface
+ if (isInUnoIncludeFile(methodDecl->getCanonicalDecl())) {
+ return true;
+ }
+
+ auto body = methodDecl->getBody();
+ if (body) {
+ auto compoundStmt = dyn_cast<CompoundStmt>(body);
+ if (!compoundStmt)
+ MarkRootOverridesNonEmpty(methodDecl->getCanonicalDecl());
+ else if (compoundStmt->size() > 0)
+ MarkRootOverridesNonEmpty(methodDecl->getCanonicalDecl());
+ }
+
+ if (!methodDecl->isThisDeclarationADefinition())
+ return true;
+
+ methodDecl = methodDecl->getCanonicalDecl();
+ if (!methodDecl)
+ return true;
+ std::string aNiceName = niceName(methodDecl);
+
+ // for destructors, we need to check if any of the superclass' destructors are virtual
+ if (isa<CXXDestructorDecl>(methodDecl)) {
+ const CXXRecordDecl* cxxRecordDecl = methodDecl->getParent();
+ if (cxxRecordDecl->getNumBases() == 0) {
+ definitionSet.insert( { aNiceName, toString( methodDecl->getLocation() ) } );
+ return true;
+ }
+ for(auto baseSpecifier = cxxRecordDecl->bases_begin();
+ baseSpecifier != cxxRecordDecl->bases_end(); ++baseSpecifier)
+ {
+ if (baseSpecifier->getType()->isRecordType())
+ {
+ const CXXRecordDecl* superclassCXXRecordDecl = baseSpecifier->getType()->getAsCXXRecordDecl();
+ if (superclassCXXRecordDecl->getDestructor())
+ {
+ std::string aOverriddenNiceName = niceName(superclassCXXRecordDecl->getDestructor());
+ overridingSet.insert(aOverriddenNiceName);
+ }
+ }
+ }
+ return true;
+ }
+
+ if (methodDecl->size_overridden_methods() == 0) {
+ definitionSet.insert( { aNiceName, toString( methodDecl->getLocation() ) } );
+ } else {
+ for (auto iter = methodDecl->begin_overridden_methods();
+ iter != methodDecl->end_overridden_methods(); ++iter)
+ {
+ const CXXMethodDecl *overriddenMethod = *iter;
+ // we only care about the first level override to establish that a virtual qualifier was useful.
+ if (overriddenMethod->isPure() || overriddenMethod->size_overridden_methods() == 0)
+ {
+ std::string aOverriddenNiceName = niceName(overriddenMethod);
+ overridingSet.insert(aOverriddenNiceName);
+ }
+ }
+ }
+ return true;
+}
+
+void UnnecessaryVirtual::MarkRootOverridesNonEmpty( const CXXMethodDecl* methodDecl )
+{
+ if (!methodDecl)
+ return;
+ if (methodDecl->size_overridden_methods() == 0) {
+ nonEmptySet.insert(niceName(methodDecl));
+ return;
+ }
+ for (auto iter = methodDecl->begin_overridden_methods();
+ iter != methodDecl->end_overridden_methods(); ++iter)
+ {
+ MarkRootOverridesNonEmpty(*iter);
+ }
+}
+
+std::string UnnecessaryVirtual::toString(SourceLocation loc)
+{
+ SourceLocation expansionLoc = compiler.getSourceManager().getExpansionLoc( loc );
+ StringRef name = getFilenameOfLocation(expansionLoc);
+ std::string sourceLocation = std::string(name.substr(strlen(SRCDIR)+1)) + ":" + std::to_string(compiler.getSourceManager().getSpellingLineNumber(expansionLoc));
+ loplugin::normalizeDotDotInFilePath(sourceLocation);
+ return sourceLocation;
+}
+
+
+loplugin::Plugin::Registration< UnnecessaryVirtual > X("unnecessaryvirtual", false);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */