/* -*- 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);
};

bool DefaultParams::VisitCallExpr(CallExpr * callExpr) {
    if (ignoreLocation(callExpr)) {
        return true;
    }
    if (callExpr->getNumArgs() == 0) {
        return true;
    }
    if (callExpr->getDirectCallee() == nullptr) {
        return true;
    }
    const FunctionDecl* functionDecl = callExpr->getDirectCallee()->getCanonicalDecl();
    unsigned i = callExpr->getNumArgs() - 1;
    Expr* arg = callExpr->getArg(i);
    // variadic functions
    if (i >= functionDecl->getNumParams()) {
        return true;
    }
    if (arg->isDefaultArgument()) {
        return true;
    }
    // ignore this, it seems to trigger an infinite recursion
    if (isa<UnaryExprOrTypeTraitExpr>(arg))
        return true;
    const ParmVarDecl* parmVarDecl = functionDecl->getParamDecl(i);
    if (!parmVarDecl->hasDefaultArg()
        || parmVarDecl->hasUninstantiatedDefaultArg())
    {
        return true;
    }
    const Expr* defaultArgExpr = parmVarDecl->getDefaultArg();
    if (defaultArgExpr &&
        defaultArgExpr->getType()->isIntegralType(compiler.getASTContext()))
    {
        APSInt x1, x2;
        if (arg->EvaluateAsInt(x1, compiler.getASTContext()) &&
            defaultArgExpr->EvaluateAsInt(x2, compiler.getASTContext()) &&
            x1 == x2)
        {
            report(
                DiagnosticsEngine::Warning,
                "not necessary to pass this argument, it defaults to the same value",
                arg->getSourceRange().getBegin())
              << arg->getSourceRange();
            /*report(
                DiagnosticsEngine::Warning,
                "default method parameter declaration here",
                parmVarDecl->getSourceRange().getBegin())
              << parmVarDecl->getSourceRange();*/
        }
    }
    return true;
}

loplugin::Plugin::Registration< DefaultParams > X("defaultparams");

}

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */