office-gobmx/compilerplugins/clang/reftotemp.cxx
Noel Grandin fb745b54d2 new loplugin:reftotemp
look for places where we are taking a reference (i.e. "&") to a
temporary object, which is misleading.

Change-Id: Id0eb4dce3f1ca559f86e02edcbea3ca17bea8e76
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175978
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Tested-by: Jenkins
2024-11-13 13:08:16 +01:00

87 lines
2.3 KiB
C++

/* -*- 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/.
*/
#ifndef LO_CLANG_SHARED_PLUGINS
#include <cassert>
#include <stack>
#include "check.hxx"
#include "plugin.hxx"
#include "config_clang.h"
/**
look for places where we take a reference (i.e. "&") to a temporary value.
Which is rather dodgy.
*/
namespace
{
class RefToTemp final : public loplugin::FilteringPlugin<RefToTemp>
{
public:
explicit RefToTemp(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
bool VisitVarDecl(const VarDecl* varDecl)
{
if (ignoreLocation(varDecl))
return true;
// reference parameters might have a default temporary value, which is ok
if (isa<ParmVarDecl>(varDecl))
return true;
if (!varDecl->getType()->isReferenceType())
return true;
if (!varDecl->getInit())
return true;
if (!isTemporaryValue(varDecl->getInit()))
return true;
report(DiagnosticsEngine::Warning, "taking reference to temporary value",
varDecl->getBeginLoc())
<< varDecl->getSourceRange();
return true;
}
bool isTemporaryValue(const Expr* expr)
{
if (dyn_cast<MaterializeTemporaryExpr>(expr))
return true;
if (auto exprWithCleanups = dyn_cast<ExprWithCleanups>(expr))
if (dyn_cast_or_null<MaterializeTemporaryExpr>(
exprWithCleanups->getSubExpr()->IgnoreImpCasts()))
return true;
return false;
}
bool preRun() override
{
if (!compiler.getLangOpts().CPlusPlus)
return false;
return true;
}
private:
void run() override
{
if (preRun())
{
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
}
};
loplugin::Plugin::Registration<RefToTemp> reftotemp("reftotemp");
}
#endif
/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */