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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 <cassert>
#include <string>
#include <iostream>
#include <unordered_map>
#include <unordered_set>
#include "plugin.hxx"
#include "check.hxx"
#include "compat.hxx"
#include "config_clang.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/StmtVisitor.h"
/**
Look for places where we are assigning a temporary O[U]String to a std::*string_view, which leads
to a view pointing to freed memory.
*/
namespace
{
class StringViewDangle : public loplugin::FilteringPlugin<StringViewDangle>
{
public:
explicit StringViewDangle(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
bool preRun() override { return true; }
virtual void run() override
{
if (!preRun())
return;
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr const*);
bool VisitVarDecl(VarDecl const*);
};
static const Expr* IgnoreImplicitAndConversionOperator(const Expr* expr)
{
expr = expr->IgnoreImplicit();
if (auto memberCall = dyn_cast<CXXMemberCallExpr>(expr))
{
if (auto conversionDecl = dyn_cast_or_null<CXXConversionDecl>(memberCall->getMethodDecl()))
{
if (!conversionDecl->isExplicit())
expr = memberCall->getImplicitObjectArgument()->IgnoreImpCasts();
}
}
return expr;
}
bool StringViewDangle::VisitCXXOperatorCallExpr(CXXOperatorCallExpr const* cxxOperatorCallExpr)
{
if (ignoreLocation(cxxOperatorCallExpr))
return true;
auto op = cxxOperatorCallExpr->getOperator();
if (op != OO_Equal)
return true;
if (!loplugin::TypeCheck(cxxOperatorCallExpr->getType())
.ClassOrStruct("basic_string_view")
.StdNamespace())
return true;
auto expr = IgnoreImplicitAndConversionOperator(cxxOperatorCallExpr->getArg(1));
auto tc = loplugin::TypeCheck(expr->getType());
if (!tc.Class("OUString").Namespace("rtl").GlobalNamespace()
&& !tc.Class("OString").Namespace("rtl").GlobalNamespace())
return true;
if (!isa<MaterializeTemporaryExpr>(expr))
return true;
report(DiagnosticsEngine::Warning, "view pointing into temporary i.e. dangling",
cxxOperatorCallExpr->getExprLoc())
<< cxxOperatorCallExpr->getSourceRange();
return true;
}
bool StringViewDangle::VisitVarDecl(VarDecl const* varDecl)
{
if (ignoreLocation(varDecl))
return true;
if (!loplugin::TypeCheck(varDecl->getType()).ClassOrStruct("basic_string_view").StdNamespace())
return true;
if (!varDecl->hasInit())
return true;
auto expr = IgnoreImplicitAndConversionOperator(varDecl->getInit());
auto tc = loplugin::TypeCheck(expr->getType());
if (!tc.Class("OUString").Namespace("rtl").GlobalNamespace()
&& !tc.Class("OString").Namespace("rtl").GlobalNamespace())
return true;
if (!isa<MaterializeTemporaryExpr>(expr))
return true;
report(DiagnosticsEngine::Warning, "view pointing into temporary i.e. dangling",
varDecl->getLocation())
<< varDecl->getSourceRange();
return true;
}
loplugin::Plugin::Registration<StringViewDangle> stringviewdangle("stringviewdangle");
}
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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