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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 <set>
#include "plugin.hxx"
// Find places where we call a method with values == the values specified in the parameter defaults.
// i.e. where the code might as well not specify anything.
namespace {
class DefaultParams:
public RecursiveASTVisitor<DefaultParams>, public loplugin::Plugin
{
public:
explicit DefaultParams(InstantiationData const & data): Plugin(data) {}
virtual void run() override { TraverseDecl(compiler.getASTContext().getTranslationUnitDecl()); }
bool VisitCallExpr(CallExpr * callExpr);
private:
bool evaluate(const Expr* expr, APSInt& x);
};
bool DefaultParams::VisitCallExpr(CallExpr * callExpr) {
if (ignoreLocation(callExpr)) {
return true;
}
if (callExpr->getDirectCallee() == nullptr) {
return true;
}
const FunctionDecl* functionDecl = callExpr->getDirectCallee()->getCanonicalDecl();
auto n = functionDecl->getNumParams();
if (n == 0 || !functionDecl->getParamDecl(n - 1)->hasDefaultArg()) {
return true;
}
assert(callExpr->getNumArgs() <= n); // can be < in template code
for (unsigned i = callExpr->getNumArgs(); i != 0;) {
--i;
Expr* arg = callExpr->getArg(i);
if (arg->isDefaultArgument()) {
continue;
}
// ignore this, it seems to trigger an infinite recursion
if (isa<UnaryExprOrTypeTraitExpr>(arg))
break;
const ParmVarDecl* parmVarDecl = functionDecl->getParamDecl(i);
if (!parmVarDecl->hasDefaultArg()
|| parmVarDecl->hasUninstantiatedDefaultArg())
{
break;
}
const Expr* defaultArgExpr = parmVarDecl->getDefaultArg();
if (!defaultArgExpr) {
break;
}
bool found = false;
if (defaultArgExpr->isNullPointerConstant(compiler.getASTContext(), Expr::NPC_NeverValueDependent)
&& arg->isNullPointerConstant(compiler.getASTContext(), Expr::NPC_NeverValueDependent))
{
found = true;
}
if (!found)
{
APSInt x1, x2;
if (evaluate(defaultArgExpr, x1) && evaluate(arg, x2) && x1 == x2)
{
found = true;
}
}
// catch params with defaults like "= OUString()"
if (!found
&& isa<MaterializeTemporaryExpr>(arg)
&& isa<MaterializeTemporaryExpr>(defaultArgExpr))
{
const CXXBindTemporaryExpr* strippedArg = dyn_cast_or_null<CXXBindTemporaryExpr>(arg->IgnoreParenCasts());
if (strippedArg && isa<CXXTemporaryObjectExpr>(strippedArg->getSubExpr())
&& dyn_cast<CXXTemporaryObjectExpr>(strippedArg->getSubExpr())->getNumArgs() == 0)
{
found = true;
}
}
if (!found)
break;
// Ignore CPPUNIT, it's macros contain some stuff that triggers us
StringRef aFileName = compiler.getSourceManager().getFilename(compiler.getSourceManager().getSpellingLoc(parmVarDecl->getLocStart()));
if (aFileName.find("include/cppunit") != std::string::npos)
break;
report(
DiagnosticsEngine::Warning,
"not necessary to pass this argument, it defaults to the same value",
arg->getSourceRange().getBegin())
<< arg->getSourceRange();
report(
DiagnosticsEngine::Note,
"default method parameter declaration here",
parmVarDecl->getSourceRange().getBegin())
<< parmVarDecl->getSourceRange();
}
return true;
}
bool DefaultParams::evaluate(const Expr* expr, APSInt& x)
{
if (isa<CXXNullPtrLiteralExpr>(expr)) {
x = 0;
return true;
}
if (expr->EvaluateAsInt(x, compiler.getASTContext()))
{
return true;
}
return false;
}
loplugin::Plugin::Registration< DefaultParams > X("defaultparams");
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
