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/* -*- 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/.
*/
#include "check.hxx"
#include "compat.hxx"
#include "plugin.hxx"
namespace
{
class RedundantFCast final : public RecursiveASTVisitor<RedundantFCast>, public loplugin::Plugin
{
public:
explicit RedundantFCast(loplugin::InstantiationData const& data)
: Plugin(data)
{
}
/* Check for the creation of unnecessary temporaries when calling a method that takes a param by const & */
bool VisitCallExpr(CallExpr const* callExpr)
{
if (ignoreLocation(callExpr))
return true;
const FunctionDecl* functionDecl;
if (isa<CXXMemberCallExpr>(callExpr))
functionDecl = dyn_cast<CXXMemberCallExpr>(callExpr)->getMethodDecl();
else
functionDecl = callExpr->getDirectCallee();
if (!functionDecl)
return true;
unsigned len = std::min(callExpr->getNumArgs(), functionDecl->getNumParams());
for (unsigned i = 0; i < len; ++i)
{
// check if param is const&
auto param = functionDecl->getParamDecl(i);
auto lvalueType = param->getType()->getAs<LValueReferenceType>();
if (!lvalueType)
continue;
if (!lvalueType->getPointeeType().isConstQualified())
continue;
auto paramClassOrStructType = lvalueType->getPointeeType()->getAs<RecordType>();
if (!paramClassOrStructType)
continue;
// check for temporary and functional cast in argument expression
auto arg = callExpr->getArg(i)->IgnoreImpCasts();
auto materializeTemporaryExpr = dyn_cast<MaterializeTemporaryExpr>(arg);
if (!materializeTemporaryExpr)
continue;
auto functionalCast = dyn_cast<CXXFunctionalCastExpr>(
materializeTemporaryExpr->GetTemporaryExpr()->IgnoreImpCasts());
if (!functionalCast)
continue;
auto const t1 = functionalCast->getTypeAsWritten();
auto const t2 = compat::getSubExprAsWritten(functionalCast)->getType();
if (t1.getCanonicalType().getTypePtr() != t2.getCanonicalType().getTypePtr())
continue;
// Check that the underlying expression is of the same class/struct type as the param i.e. that we are not instantiating
// something useful
if (t1.getCanonicalType().getTypePtr() != paramClassOrStructType)
continue;
report(DiagnosticsEngine::Warning, "redundant functional cast from %0 to %1",
arg->getExprLoc())
<< t2 << t1 << arg->getSourceRange();
report(DiagnosticsEngine::Note, "in call to method here", param->getLocation())
<< param->getSourceRange();
}
return true;
}
bool VisitCXXFunctionalCastExpr(CXXFunctionalCastExpr const* expr)
{
if (ignoreLocation(expr))
return true;
auto const t1 = expr->getTypeAsWritten();
auto const t2 = compat::getSubExprAsWritten(expr)->getType();
if (t1.getCanonicalType().getTypePtr() != t2.getCanonicalType().getTypePtr())
{
return true;
}
auto tc = loplugin::TypeCheck(t1);
if (!(tc.Class("OUString").Namespace("rtl").GlobalNamespace()
|| tc.Class("Color").GlobalNamespace() || tc.Class("unique_ptr").StdNamespace()))
{
return true;
}
report(DiagnosticsEngine::Warning, "redundant functional cast from %0 to %1",
expr->getExprLoc())
<< t2 << t1 << expr->getSourceRange();
return true;
}
private:
void run() override
{
if (compiler.getLangOpts().CPlusPlus)
{
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
}
};
static loplugin::Plugin::Registration<RedundantFCast> reg("redundantfcast");
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
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