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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/.
*/
#include <string>
#include <iostream>
#include <unordered_set>
#include "plugin.hxx"
#include "check.hxx"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/StmtVisitor.h"
/*
Mike Kaganski found a bug where the code was looping over a block and
not using the index var, and the loop was unnecessary.
So he wanted to have a look for other places like that.
*/
namespace
{
class UnusedIndex : public loplugin::FilteringPlugin<UnusedIndex>
{
public:
explicit UnusedIndex(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
bool TraverseForStmt(ForStmt* stmt);
bool VisitDeclRefExpr(DeclRefExpr const* stmt);
private:
std::vector<VarDecl const*> mLoopVarDecls;
std::unordered_set<VarDecl const*> mFoundSet;
};
bool UnusedIndex::TraverseForStmt(ForStmt* stmt)
{
if (ignoreLocation(stmt))
return true;
VarDecl const* loopVarDecl = nullptr;
if (stmt->getInit())
{
auto declStmt = dyn_cast<DeclStmt>(stmt->getInit());
if (declStmt && declStmt->isSingleDecl())
{
loopVarDecl = dyn_cast<VarDecl>(declStmt->getSingleDecl());
}
}
if (loopVarDecl)
mLoopVarDecls.push_back(loopVarDecl);
// deliberately ignore the other parts of the for stmt, except for the body
auto ret = RecursiveASTVisitor::TraverseStmt(stmt->getBody());
if (loopVarDecl && mFoundSet.erase(loopVarDecl) == 0)
report(DiagnosticsEngine::Warning, "loop variable not used", loopVarDecl->getBeginLoc())
<< loopVarDecl->getSourceRange();
if (loopVarDecl)
mLoopVarDecls.pop_back();
return ret;
}
bool UnusedIndex::VisitDeclRefExpr(DeclRefExpr const* stmt)
{
auto varDecl = dyn_cast<VarDecl>(stmt->getDecl());
if (!varDecl)
return true;
if (std::find(mLoopVarDecls.begin(), mLoopVarDecls.end(), varDecl) != mLoopVarDecls.end())
mFoundSet.insert(varDecl);
return true;
}
loplugin::Plugin::Registration<UnusedIndex> X("unusedindex", false);
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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