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-rw-r--r--compilerplugins/clang/rangedforcopy.cxx70
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diff --git a/compilerplugins/clang/rangedforcopy.cxx b/compilerplugins/clang/rangedforcopy.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/.
+ */
+#ifndef LO_CLANG_SHARED_PLUGINS
+
+#include <string>
+#include <iostream>
+
+#include "plugin.hxx"
+#include "clang/AST/CXXInheritance.h"
+
+// Check that we're not unnecessarily copying variables in a range based for loop
+// e.g. "for (OUString a: aList)" results in a copy of each string being made,
+// whereas "for (const OUString& a: aList)" does not.
+
+namespace
+{
+
+class RangedForCopy:
+ public loplugin::FilteringPlugin<RangedForCopy>
+{
+public:
+ explicit RangedForCopy(loplugin::InstantiationData const & data):
+ FilteringPlugin(data) {}
+
+ virtual void run() override {
+ if (preRun())
+ TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
+ }
+
+ bool VisitCXXForRangeStmt( const CXXForRangeStmt* stmt );
+};
+
+bool RangedForCopy::VisitCXXForRangeStmt( const CXXForRangeStmt* stmt )
+{
+ if (ignoreLocation( stmt ))
+ return true;
+
+ const VarDecl* varDecl = stmt->getLoopVariable();
+ if (!varDecl)
+ return true;
+
+ const QualType type = varDecl->getType();
+ if (type->isRecordType() && !type->isReferenceType() && !type->isPointerType())
+ {
+ std::string name = type.getAsString();
+ report(
+ DiagnosticsEngine::Warning,
+ "Loop variable passed by value, pass by reference instead, e.g. 'const %0&'",
+ compat::getBeginLoc(varDecl))
+ << name << varDecl->getSourceRange();
+ }
+
+ return true;
+}
+
+
+loplugin::Plugin::Registration< RangedForCopy > rangedforcopy("rangedforcopy");
+
+} // namespace
+
+#endif // LO_CLANG_SHARED_PLUGINS
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */