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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 "plugin.hxx"
#include "check.hxx"
#include "llvm/ADT/Optional.h"
#include <iostream>
/**
TODO multiplying/otherop on a combination of a float and int, and then truncating to int. like this:
float getRotation() {}
int moRotation = -F_PI180 * 90 * getRotation();
*/
namespace
{
class IntVsFloat : public loplugin::FilteringPlugin<IntVsFloat>
{
public:
explicit IntVsFloat(loplugin::InstantiationData const& data)
: loplugin::FilteringPlugin<IntVsFloat>(data)
{
}
void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
bool VisitVarDecl(VarDecl const*);
bool VisitBinaryOperator(BinaryOperator const*);
private:
llvm::Optional<double> getExprValue(Expr const* expr);
};
bool IntVsFloat::VisitVarDecl(VarDecl const* varDecl)
{
if (ignoreLocation(varDecl->getLocation()))
return true;
auto init = varDecl->getInit();
if (!init)
return true;
init = init->IgnoreImpCasts();
if (varDecl->getType()->isFloatingType())
return true;
// init->dump();
llvm::Optional<double> d = getExprValue(init);
if (!d)
return true;
if (static_cast<long>(*d) == *d)
return true;
report(DiagnosticsEngine::Warning, "assigning constant float value to int truncates data",
init->getBeginLoc())
<< init->getSourceRange();
return true;
}
bool IntVsFloat::VisitBinaryOperator(BinaryOperator const* op)
{
if (op->getOpcode() != BO_EQ)
{
return true;
}
if (ignoreLocation(op->getBeginLoc()))
return true;
auto lhs = op->getLHS()->IgnoreImpCasts();
auto rhs = op->getRHS()->IgnoreImpCasts();
if (!lhs->getType()->isFloatingType())
std::swap(lhs, rhs);
if (!lhs->getType()->isFloatingType())
return true;
if (rhs->getType()->isFloatingType())
return true;
llvm::Optional<double> d = getExprValue(lhs);
if (!d)
return true;
if (static_cast<long>(*d) == *d)
return true;
report(DiagnosticsEngine::Warning, "comparing integer to float constant, can never be true",
op->getBeginLoc())
<< op->getSourceRange();
return true;
}
llvm::Optional<double> IntVsFloat::getExprValue(Expr const* expr)
{
// Of the available clang Evaluate* APIs, this is the __only__ one that produces useful output
// (as of 17 Aug 2018 checkout of clang, ie. towards clang 7)
if (expr->isValueDependent())
return llvm::Optional<double>();
Expr::EvalResult evalResult;
if (!expr->EvaluateAsRValue(evalResult, compiler.getASTContext()))
return llvm::Optional<double>();
if (!evalResult.Val.isFloat())
return llvm::Optional<double>();
llvm::APFloat floatResult = evalResult.Val.getFloat();
bool losesInfo;
floatResult.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &losesInfo);
double d = floatResult.convertToDouble();
return d;
}
loplugin::Plugin::Registration<IntVsFloat> intvsfloat("intvsfloat");
} // namespace
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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