TPEFSymbolSectionWriter.cc

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
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    the rights to use, copy, modify, merge, publish, distribute, sublicense,
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    Software is furnished to do so, subject to the following conditions:
 
    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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/**
 * @file TPEFSymbolSectionWriter.cc
 *
 * Definition of TPEFSymbolSectionWriter class.
 *
 * @author Mikael Lepistö 2004 (tmlepist-no.spam-cs.tut.fi)
 *
 * @note rating: yellow
 */
 
#include <list>
 
#include "TPEFSymbolSectionWriter.hh"
#include "SafePointer.hh"
#include "ReferenceKey.hh"
#include "SectionElement.hh"
#include "SectionSizeReplacer.hh"
#include "SectionOffsetReplacer.hh"
#include "SectionIdReplacer.hh"
#include "NoTypeSymElement.hh"
#include "CodeSymElement.hh"
#include "ProcedSymElement.hh"
#include "DataSymElement.hh"
#include "FileSymElement.hh"
#include "SectionSymElement.hh"
#include "BinaryStream.hh"
 
namespace TPEF {
 
using std::list;
using ReferenceManager::SafePointer;
using ReferenceManager::SectionKey;
using ReferenceManager::FileOffsetKey;
using ReferenceManager::SectionIndexKey;
 
const TPEFSymbolSectionWriter TPEFSymbolSectionWriter::instance_;
const Word TPEFSymbolSectionWriter::elementSize_ = 16;
 
/**
 * Constructor.
 *
 * Registers itself to SectionWriter.
 */
TPEFSymbolSectionWriter::TPEFSymbolSectionWriter() : TPEFSectionWriter() {
    registerSectionWriter(this);
}
 
/**
 * Destructor.
 */
TPEFSymbolSectionWriter::~TPEFSymbolSectionWriter() {
}
 
/**
 * Returns the section type this writer can write.
 *
 * @return The section type writer can write.
 */
Section::SectionType
TPEFSymbolSectionWriter::type() const {
    return Section::ST_SYMTAB;
}
 
/**
 * Writes the data of the section in to stream.
 *
 * @param stream The stream to be written to.
 * @param sect The section to be written.
 */
void
TPEFSymbolSectionWriter::actualWriteData(
    BinaryStream& stream,
    const Section* sect) const {
 
    FileOffset startOffset = stream.writePosition();
 
    // file offset to data of section
    SafePointer::addObjectReference(
        FileOffsetKey(startOffset), sect->element(0));
 
    // resolve identification code of currently written section
    SectionKey sectionKey = SafePointer::sectionKeyFor(sect);
    SectionId sectionId = sectionKey.sectionId();
 
    // first element should match with undefined symbol
    SymbolElement *undef = dynamic_cast<SymbolElement*>(sect->element(0));
    assert(undef != NULL);
    assert(undef->type() == SymbolElement::STT_NOTYPE);
    assert(undef->absolute() == true);
    assert(undef->binding() == SymbolElement::STB_LOCAL);
    assert(undef->name()->offset() == 0);
 
    // symbols might have to be organized in a way local symbols are
    // before weak symbols and global syms will come after everything else
    for (Word i = 0; i < sect->elementCount(); i++) {
 
        SymbolElement* elem = dynamic_cast<SymbolElement*>(sect->element(i));
        assert(elem != NULL);
 
        // each element must be registered with its index
        SafePointer::addObjectReference(
            SectionIndexKey(sectionId, i), elem);
 
        // write name
        assert(elem->name() != NULL);
        SectionOffsetReplacer sOffReplacer(elem->name());
        sOffReplacer.resolve();
 
        writeValueAndSize(stream, elem);
 
        // write info
        stream.writeByte(
            (elem->binding() << (BYTE_BITWIDTH / 2)) |
            static_cast<Byte>(elem->type()));
 
        // other field,  right now only STO_ABS is used
        Byte otherField = 0;
        if (elem->absolute()) {
            otherField = otherField | TPEFHeaders::STO_ABS;
        }
        stream.writeByte(otherField);
 
        // section to which the symbol belongs
        // NOTE: Maybe nullSection should be used for these,
        //       so NULL would be error.
 
        if (elem->section() != NULL) {
            SectionIdReplacer sectIdReplacer(elem->section());
            sectIdReplacer.resolve();
        } else {
            stream.writeHalfWord(0);
        }
    }
    SectionSizeReplacer::setSize(sect, stream.writePosition() - startOffset);
}
 
/**
 * Writes value and size fields of symbol.
 *
 * @param stream Stream where to write.
 * @param elem Element to write.
 */
void
TPEFSymbolSectionWriter::writeValueAndSize(
    BinaryStream &stream,
    const SymbolElement *elem) const {
 
    switch (elem->type()) {
    case SymbolElement::STT_NOTYPE: {
        // write value
        // write size
        stream.writeWord(0);
        stream.writeWord(0);
        break;
    }
 
    case SymbolElement::STT_PROCEDURE:
    case SymbolElement::STT_CODE: {
        const CodeSymElement* codeSym =
            dynamic_cast<const CodeSymElement*>(elem);
        assert(codeSym != NULL);
 
        // write value
        if (codeSym->reference() != NULL) {
            SectionOffsetReplacer replacer(codeSym->reference());
            replacer.resolve();
        } else {
            stream.writeWord(0);
        }
 
        // write size
        stream.writeWord(codeSym->size());
        break;
    }
 
    case SymbolElement::STT_DATA: {
        const DataSymElement* dataSym =
            dynamic_cast<const DataSymElement*>(elem);
        assert(dataSym != NULL);
 
        // write value
        if (dataSym->reference() != NULL) {
            SectionOffsetReplacer replacer(dataSym->reference());
            replacer.resolve();
        } else {
            stream.writeWord(0);
        }
 
        // write size
        stream.writeWord(dataSym->size());
        break;
    }
 
    case SymbolElement::STT_SECTION: {
        const SectionSymElement* sectSym =
            dynamic_cast<const SectionSymElement*>(elem);
        assert(sectSym != NULL);
 
        // write value
        stream.writeWord(sectSym->value());
        // write size
        stream.writeWord(sectSym->size());
        break;
    }
 
    case SymbolElement::STT_FILE: {
        const FileSymElement* fileSym =
            dynamic_cast<const FileSymElement*>(elem);
        assert(fileSym != NULL);
 
        // write value
        stream.writeWord(fileSym->value());
        // write size
        stream.writeWord(0);
        break;
    }
 
    default: {
        bool unknownSymbolType = false;
        assert(unknownSymbolType);
    }
    }
}
 
/**
 * Returns the fixed size length of section elements.
 *
 * @return The fixed size length of section elements.
 */
Word
TPEFSymbolSectionWriter::elementSize(const Section* /*section*/) const {
    return elementSize_;
}
 
/**
 * Creates needed keys for section if noBits flag is set.
 *
 * @param sect Section which for keys will be created.
 */
void
TPEFSymbolSectionWriter::createKeys(const Section* sect) const {
    SectionSizeReplacer::setSize(sect, 0x0);
}
 
}