Files
libreoffice/compilerplugins/clang/faileddyncast.cxx
Noel Grandin 9f4d23c151 filter out some of the AST in the plugins
by checking if the current namespace decl is in our code, so we have to
scan less stuff, which results in a 10% perf improvement for me

Change-Id: Idf0e30d57b6d0dcd13daa9ed679c28b9d233d387
Reviewed-on: https://gerrit.libreoffice.org/58942
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
2018-08-14 13:02:14 +02:00

131 lines
3.4 KiB
C++

/* -*- 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 <algorithm>
#include "clang/AST/Attr.h"
#include "clang/AST/CXXInheritance.h"
#include "plugin.hxx"
namespace {
// cf. Clang's clang::AST::CXXDynamicCastExpr::isAlwaysNull
// (lib/AST/ExprCXX.cpp):
bool isAlwaysNull(CXXDynamicCastExpr const * expr) {
QualType SrcType = expr->getSubExpr()->getType();
QualType DestType = expr->getType();
if (const clang::PointerType *SrcPTy = SrcType->getAs<clang::PointerType>()) {
SrcType = SrcPTy->getPointeeType();
#if 0
DestType = DestType->castAs<PointerType>()->getPointeeType();
#else
auto DstPTy = DestType->getAs<clang::PointerType>();
if (!DstPTy)
return false;
DestType = DstPTy->getPointeeType();
#endif
}
if (DestType->isVoidType())
return false;
#if 0
const CXXRecordDecl *SrcRD =
cast<CXXRecordDecl>(SrcType->castAs<RecordType>()->getDecl());
#else
auto SrcRT = SrcType->getAs<RecordType>();
if (!SrcRT)
return false;
const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(SrcRT->getDecl());
#endif
#if 0
if (!SrcRD->hasAttr<FinalAttr>())
return false;
#endif
#if 0
const CXXRecordDecl *DestRD =
cast<CXXRecordDecl>(DestType->castAs<RecordType>()->getDecl());
#else
auto DestRT = DestType->getAs<RecordType>();
if (!DestRT)
return false;
const CXXRecordDecl *DestRD = cast<CXXRecordDecl>(DestRT->getDecl());
#endif
#if 1
if (!(SrcRD && DestRD))
return false;
if (DestRD->hasAttr<FinalAttr>()) {
CXXBasePaths Paths(/*FindAmbiguities=*/false, /*RecordPaths=*/true,
/*DetectVirtual=*/false);
if (DestRD->isDerivedFrom(SrcRD, Paths) &&
std::all_of(Paths.begin(), Paths.end(),
[](CXXBasePath const & Path) {
return Path.Access != AS_public; }))
return true;
}
if (!SrcRD->hasAttr<FinalAttr>())
return false;
#endif
#if 0
return !DestRD->isDerivedFrom(SrcRD);
#else
return !(DestRD->isDerivedFrom(SrcRD)
|| SrcRD->isDerivedFrom(DestRD)
|| SrcRD == DestRD);
#endif
}
class FailedDynCast:
public loplugin::FilteringPlugin<FailedDynCast>
{
public:
explicit FailedDynCast(loplugin::InstantiationData const & data):
FilteringPlugin(data) {}
bool shouldVisitTemplateInstantiations() const { return true; }
void run() override;
bool VisitCXXDynamicCastExpr(CXXDynamicCastExpr const * expr);
};
void FailedDynCast::run() {
if (compiler.getLangOpts().CPlusPlus) {
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
}
bool FailedDynCast::VisitCXXDynamicCastExpr(CXXDynamicCastExpr const * expr) {
if (ignoreLocation(expr)) {
return true;
}
if (isAlwaysNull(expr)) {
report(
DiagnosticsEngine::Warning,
"dynamic_cast from %0 to %1 always fails", compat::getBeginLoc(expr))
<< expr->getSubExpr()->getType() << expr->getType()
<< expr->getSourceRange();
}
return true;
}
loplugin::Plugin::Registration<FailedDynCast> X("faileddyncast");
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */