/*
     Copyright 2017 Wolfgang Thaller.

     This file is part of Retro68.

     Retro68 is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
     (at your option) any later version.

     Retro68 is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with Retro68.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "Symtab.h"

#include <assert.h>
#include <utility>

#include "Symbol.h"

using std::make_pair;
using std::string;

Symtab::Symtab(Object& theObject, Elf_Scn *elfsec)
    : elfsec(elfsec)
{
    data = elf_getdata(elfsec, NULL);

    GElf_Shdr shdr;
    gelf_getshdr(elfsec, &shdr);

    int count = shdr.sh_size / shdr.sh_entsize;
    symbols.reserve(count);

    for(int i = 0; i < count; i++)
    {
        GElf_Sym sym;
        auto res = gelf_getsym(data, i, &sym);
        assert(res != 0);
        symbols.emplace_back(theObject, sym);

        if(sym.st_shndx != SHN_UNDEF && sym.st_shndx < SHN_LORESERVE)
            symbolsByAddress[make_pair((int)sym.st_shndx,sym.st_value)] = i;
        if(sym.st_name)
            symbolsByName[symbols.back().name] = i;
    }
}

Symtab::~Symtab()
{

}

Symbol &Symtab::GetSym(int idx)
{
    return symbols[idx];
}

int Symtab::FindSym(int secidx, uint32_t addr)
{
    auto p = symbolsByAddress.find(make_pair(secidx, addr));
    if(p != symbolsByAddress.end())
        return p->second;
    else
        return -1;
}

int Symtab::FindSym(string name)
{
    auto p = symbolsByName.find(name);
    if(p != symbolsByName.end())
        return p->second;
    else
        return -1;
}