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343 | /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* Based on LLVM/Clang.
*
* This file is distributed under the University of Illinois Open Source
* License. See LICENSE.TXT for details.
*
*/
#include "config_clang.h"
#include <config_global.h>
#include "plugin.hxx"
#include "compat.hxx"
#include "check.hxx"
#include <unordered_set>
#include <unordered_map>
#if CLANG_VERSION >= 110000
#include "clang/AST/ParentMapContext.h"
#endif
namespace loplugin
{
/*
This is a compile check. The results of this plugin need to be checked by hand, since it is a collection of heuristics.
Check for unused variable where
(*) we never call methods that return information from the variable.
(*) we never pass the variable to anything else
Classes which are safe to be warned about need to be marked using
SAL_WARN_UNUSED (see e.g. OUString). For external classes such as std::vector
that cannot be edited there is a manual list.
This is an expensive plugin, since it walks up the parent tree,
so it is off by default.
*/
class UnusedVariableMore : public loplugin::FilteringPlugin<UnusedVariableMore>
{
public:
explicit UnusedVariableMore(const InstantiationData& data);
virtual void run() override;
bool VisitVarDecl(VarDecl const*);
bool VisitDeclRefExpr(DeclRefExpr const*);
bool VisitFunctionDecl(FunctionDecl const*);
private:
bool checkifUnused(Stmt const*, VarDecl const*);
bool isOkForParameter(const QualType&);
std::unordered_set<VarDecl const*> interestingSet;
// used to dump the last place that said the usage was unused, for debug purposes
std::unordered_map<VarDecl const*, Stmt const*> interestingDebugMap;
};
UnusedVariableMore::UnusedVariableMore(const InstantiationData& data)
: FilteringPlugin(data)
{
}
void UnusedVariableMore::run()
{
std::string fn(handler.getMainFileName());
loplugin::normalizeDotDotInFilePath(fn);
// ignore QA folders
if (loplugin::hasPathnamePrefix(fn, SRCDIR "/sal/qa/"))
return;
if (loplugin::hasPathnamePrefix(fn, SRCDIR "/i18npool/qa/"))
return;
if (loplugin::hasPathnamePrefix(fn, SRCDIR "/sc/qa/"))
return;
// vector of shared_ptr used to delay destruction
if (fn == SRCDIR "/cppuhelper/source/servicemanager.cxx")<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
if (fn == SRCDIR "/i18nlangtag/source/languagetag/languagetag.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// unordered_set of Reference to delay destruction
if (fn == SRCDIR "/stoc/source/servicemanager/servicemanager.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// TODO "operator >>" fooling me here
if (fn == SRCDIR "/editeng/source/accessibility/AccessibleEditableTextPara.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// some weird stuff
if (fn == SRCDIR "/sfx2/source/dialog/dinfdlg.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// std::vector< Reference< XInterface > > keep alive
if (fn == SRCDIR "/dbaccess/source/core/dataaccess/databasedocument.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// template magic
if (fn == SRCDIR "/sc/source/core/tool/scmatrix.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// storing local copy of Link<>
if (fn == SRCDIR "/sc/source/ui/miscdlgs/simpref.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// Using an SwPaM to do stuff
if (fn == SRCDIR "/sw/source/core/crsr/bookmrk.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// index variable in for loop?
if (fn == SRCDIR "/sw/source/uibase/docvw/edtwin.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// TODO "operator >>" fooling me here
if (fn == SRCDIR "/sw/source/filter/ww8/ww8par.cxx")<--- Testing identical condition 'fn==SRCDIR'<--- If condition 'fn==SRCDIR' is true, the function will return/exit
return;
// TODO "operator >>" fooling me here
if (fn == SRCDIR "/sc/source/filter/excel/xistream.cxx")<--- Testing identical condition 'fn==SRCDIR'
return;
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
for (VarDecl const* varDecl : interestingSet)
{
report(DiagnosticsEngine::Warning, "unused variable %0", varDecl->getLocation())
<< varDecl->getDeclName();
//auto it = interestingDebugMap.find(varDecl);
//if (it != interestingDebugMap.end())
// it->second->dump();
}
}
bool isWarnUnusedType(QualType type)
{
if (auto const t = type->getAs<TypedefType>())
{
if (t->getDecl()->hasAttr<WarnUnusedAttr>())
{
return true;
}
}
if (auto const t = type->getAs<RecordType>())
{
if (t->getDecl()->hasAttr<WarnUnusedAttr>())
{
return true;
}
}
return loplugin::isExtraWarnUnusedType(type);
}
bool UnusedVariableMore::VisitVarDecl(VarDecl const* var)
{
if (ignoreLocation(var))
return true;
if (var->isDefinedOutsideFunctionOrMethod())
return true;
if (isa<ParmVarDecl>(var))
return true;
if (!isWarnUnusedType(var->getType()))
return true;
// some false +
auto dc = loplugin::TypeCheck(var->getType());
if (dc.Class("ZCodec").GlobalNamespace())
return true;
if (dc.Class("ScopedVclPtrInstance").GlobalNamespace())
return true;
if (dc.Class("VclPtrInstance").GlobalNamespace())
return true;
if (dc.Class("Config").GlobalNamespace())
return true;
// I think these classes modify global state somehow
if (dc.Class("SvtHistoryOptions").GlobalNamespace())
return true;
if (dc.Class("SvtSecurityOptions").GlobalNamespace())
return true;
if (dc.Class("SvtViewOptions").GlobalNamespace())
return true;
if (dc.Class("SvtUserOptions").GlobalNamespace())
return true;
if (dc.Class("SvtFontOptions").GlobalNamespace())
return true;
if (dc.Class("SvtMenuOptions").GlobalNamespace())
return true;
if (dc.Class("SvtPathOptions").GlobalNamespace())
return true;
if (dc.Class("SvtPrintWarningOptions").GlobalNamespace())
return true;
if (dc.Class("SvtSysLocaleOptions").GlobalNamespace())
return true;
interestingSet.insert(var);
return true;
}
bool UnusedVariableMore::VisitDeclRefExpr(DeclRefExpr const* declRefExpr)
{
if (ignoreLocation(declRefExpr))
return true;
auto varDecl = dyn_cast<VarDecl>(declRefExpr->getDecl());
if (!varDecl)
return true;
if (interestingSet.find(varDecl) == interestingSet.end())
return true;
if (!checkifUnused(declRefExpr, varDecl))
interestingSet.erase(varDecl);
return true;
}
// Walk up from a statement that contains a DeclRefExpr, checking if the usage means that the
// related VarDecl is unused.
bool UnusedVariableMore::checkifUnused(Stmt const* stmt, VarDecl const* varDecl)
{
const Stmt* parent = getParentStmt(stmt);
if (!parent)
{
// check if we're inside a CXXCtorInitializer
auto parentsRange = getParents(*stmt);
if (parentsRange.begin() != parentsRange.end())
{
auto parentDecl = parentsRange.begin()->get<Decl>();
if (parentDecl && (isa<CXXConstructorDecl>(parentDecl) || isa<VarDecl>(parentDecl)))
return false;
}
interestingDebugMap[varDecl] = stmt;
return true;
}
if (isa<ReturnStmt>(parent))
return false;
if (isa<IfStmt>(parent))
return false;
if (isa<SwitchStmt>(parent))
return false;
if (isa<InitListExpr>(parent))
return false;
if (isa<CXXConstructExpr>(parent))
return false;
if (isa<BinaryOperator>(parent))
return false;
if (isa<UnaryOperator>(parent))
return false;
if (isa<ConditionalOperator>(parent))
return false;
if (isa<ArraySubscriptExpr>(parent))
return false;
if (isa<CXXBindTemporaryExpr>(parent))
return checkifUnused(parent, varDecl);
if (isa<MaterializeTemporaryExpr>(parent))
return checkifUnused(parent, varDecl);
if (isa<CompoundStmt>(parent))
{
interestingDebugMap[varDecl] = parent;
return true;
}
// check for cast to void
if (auto explicitCastExpr = dyn_cast<ExplicitCastExpr>(parent))
{
if (loplugin::TypeCheck(explicitCastExpr->getTypeAsWritten()).Void())
return false;
}
if (isa<MemberExpr>(parent))
return checkifUnused(parent, varDecl);
if (isa<ExprWithCleanups>(parent))
return checkifUnused(parent, varDecl);
if (isa<CastExpr>(parent))
return checkifUnused(parent, varDecl);
if (isa<ParenExpr>(parent))
return checkifUnused(parent, varDecl);
if (auto operatorCallExpr = dyn_cast<CXXOperatorCallExpr>(parent))
{
const CXXMethodDecl* calleeMethodDecl
= dyn_cast_or_null<CXXMethodDecl>(operatorCallExpr->getDirectCallee());
if (calleeMethodDecl)
{
if (calleeMethodDecl->getNumParams() == 0)
return checkifUnused(parent, varDecl);
if (operatorCallExpr->getArg(0) == stmt)
return checkifUnused(parent, varDecl);
}
}
if (auto memberCallExpr = dyn_cast<CXXMemberCallExpr>(parent))
{
const MemberExpr* memberExpr = dyn_cast<MemberExpr>(stmt);
if (memberExpr && memberCallExpr->getImplicitObjectArgument() == memberExpr->getBase())
{
// if we are calling a method on the varDecl, walk up
if (!checkifUnused(parent, varDecl))
return false;
// check if we are passing something to the var by non-const ref, in which case it is updating something else for us
const FunctionDecl* calleeFunctionDecl = memberCallExpr->getDirectCallee();
if (calleeFunctionDecl)
{
if (calleeFunctionDecl->isVariadic())
return false;
for (unsigned i = 0; i < memberCallExpr->getNumArgs(); ++i)
{
if (i >= calleeFunctionDecl->getNumParams()) // can happen in template code
{
interestingDebugMap[varDecl] = parent;
return true;
}
if (!isOkForParameter(calleeFunctionDecl->getParamDecl(i)->getType()))
return false;
}
}
interestingDebugMap[varDecl] = parent;
return true;
}
}
if (isa<CallExpr>(parent))
return false;
interestingDebugMap[varDecl] = parent;
return true;
}
bool UnusedVariableMore::isOkForParameter(const QualType& qt)
{
if (qt->isIntegralOrEnumerationType())
return true;
auto const type = loplugin::TypeCheck(qt);
if (type.Pointer())
{
return bool(type.Pointer().Const());
}
else if (type.LvalueReference())
{
return bool(type.LvalueReference().Const());
}
return false;
}
bool UnusedVariableMore::VisitFunctionDecl(FunctionDecl const* functionDecl)
{
if (ignoreLocation(functionDecl))
return true;
//functionDecl->dump();
return true;
}
static Plugin::Registration<UnusedVariableMore> X("unusedvariablemore", false);
} // namespace
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|