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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 "check.hxx"
#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;
if (isa<DecompositionDecl>(varDecl))
{
// Assume that use of a non-reference structured binding is intentional:
return true;
}
const QualType type = varDecl->getType();
if (!type->isRecordType() || type->isReferenceType() || type->isPointerType())
return true;
if (auto exprWithCleanups = dyn_cast<ExprWithCleanups>(varDecl->getInit()))
if (dyn_cast<CXXBindTemporaryExpr>(exprWithCleanups->getSubExpr()->IgnoreImpCasts()))
return true;
if (loplugin::TypeCheck(type).Class("__bit_const_reference").StdNamespace())
{
// With libc++ without _LIBCPP_ABI_BITSET_VECTOR_BOOL_CONST_SUBSCRIPT_RETURN_BOOL,
// iterating over a const std::vector<bool> non-compliantly uses a variable of some
// internal __bit_const_reference class type, rather than of type bool (see
// <https://reviews.llvm.org/D123851> "[libc++] Change
// vector<bool>::const_iterator::reference to bool in ABIv2"):
return true;
}
// trivial class, ignore it
if (loplugin::TypeCheck(type).Class("TypedWhichId").GlobalNamespace())
return true;
if (loplugin::TypeCheck(type).Typedef("OUStringChar").Namespace("rtl"))
return true;
std::string name = type.getAsString();
report(
DiagnosticsEngine::Warning,
"Loop variable passed by value, pass by reference instead, e.g. 'const %0&'",
varDecl->getBeginLoc())
<< name << varDecl->getSourceRange();
return true;
}
loplugin::Plugin::Registration< RangedForCopy > rangedforcopy("rangedforcopy");
} // namespace
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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