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// attributes.cc -- object attributes for gold

// Copyright 2009 Free Software Foundation, Inc.

// Written by Doug Kwan <dougkwan@google.com>.

// This file contains code adapted from BFD.

// This file is part of gold.

// This program 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.

// This program 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 this program; if not, write to the Free Software

// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,

// MA 02110-1301, USA.

#include "gold.h"

#include <limits>

#include "attributes.h"

#include "elfcpp.h"

#include "target.h"

#include "parameters.h"

#include "int_encoding.h"

namespace gold

{

// Object_attribute methods.

// Return size of attribute encode in ULEB128.

size_t

Object_attribute::size(int tag) const

{

  // Attributes with default values are not written out.

  if (this->is_default_attribute())

    return 0;

  size_t size = get_length_as_unsigned_LEB_128(tag);

  if (Object_attribute::attribute_type_has_int_value(this->type_))

    size += get_length_as_unsigned_LEB_128(this->int_value_);

  if (Object_attribute::attribute_type_has_string_value(this->type_))

    size += this->string_value_.size() + 1;

  return size;

}

// Whether this has the default value (0/"").

bool

Object_attribute::is_default_attribute() const

{

  if (Object_attribute::attribute_type_has_int_value(this->type_)

      && this->int_value_ != 0)

    return false;

  if (Object_attribute::attribute_type_has_string_value(this->type_)

      && !this->string_value_.empty())

    return false;

  if (Object_attribute::attribute_type_has_no_default(this->type_))

    return false;

  return true;

}

// Whether this matches another Object_attribute OA in merging.

// Two Object_attributes match if they have the same values.

bool

Object_attribute::matches(const Object_attribute& oa) const

{

  return ((this->int_value_ != oa.int_value_)

          && (this->string_value_ == oa.string_value_));

}

// Write this with TAG to a BUFFER.

void

Object_attribute::write(

    int tag,

    std::vector<unsigned char>* buffer) const

{

  // No need to write default attributes.

  if (this->is_default_attribute())

    return;

  // Write tag.

  write_unsigned_LEB_128(buffer, convert_types<uint64_t, int>(tag));

  // Write integer value.

  if (Object_attribute::attribute_type_has_int_value(this->type_))

    write_unsigned_LEB_128(buffer,

                           convert_types<uint64_t, int>(this->int_value_));

  // Write string value.

  if (Object_attribute::attribute_type_has_string_value(this->type_))

    {

      const unsigned char* start =

        reinterpret_cast<const unsigned char*>(this->string_value_.c_str());

      const unsigned char* end = start + this->string_value_.size() + 1;

      buffer->insert(buffer->end(), start, end);

    }

}

// Vendor_object_attributes methods.

// Copying constructor.

Vendor_object_attributes::Vendor_object_attributes(

    const Vendor_object_attributes& voa)

{

  this->vendor_ = voa.vendor_;

  for (int i = 0; i < NUM_KNOWN_ATTRIBUTES; ++i)

    this->known_attributes_[i] = voa.known_attributes_[i];

  // We do not handle attribute deletion.  So this must be empty.

  gold_assert(this->other_attributes_.empty());

  for (Other_attributes::const_iterator p = voa.other_attributes_.begin();

       p != voa.other_attributes_.end();

       ++p)

    this->other_attributes_[p->first] = new Object_attribute(*(p->second));

}

// Size of this in number of bytes.

size_t

Vendor_object_attributes::size() const

{

  if (this->name() == NULL)

    return 0;

  size_t data_size = 0;

  for (int i = 4; i < NUM_KNOWN_ATTRIBUTES; ++i)

    data_size += this->known_attributes_[i].size(i);

  for (Other_attributes::const_iterator p = this->other_attributes_.begin();

       p != this->other_attributes_.end();

       ++p)

    data_size += p->second->size(p->first);

  // <size> <vendor_name> NUL 0x1 <size>

  return ((data_size != 0

           || this->vendor_ == Object_attribute::OBJ_ATTR_PROC)

          ? data_size + strlen(this->name()) + 2 + 2 * 4

          : 0);

}

// Return a new attribute associated with TAG.

Object_attribute*

Vendor_object_attributes::new_attribute(int tag)

{

  int type = Object_attribute::arg_type(this->vendor_, tag);

  if (tag < NUM_KNOWN_ATTRIBUTES)

    {

      this->known_attributes_[tag].set_type(type);

      return &this->known_attributes_[tag];

    }

  else

    {

      Object_attribute* attr = new Object_attribute();

      // This should be the first time we insert this.

      std::pair<Other_attributes::iterator, bool> ins =

        this->other_attributes_.insert(std::make_pair(tag, attr));

      gold_assert(ins.second);

      attr->set_type(type);

      return attr;

    }

}

// Return an attribute associated with TAG.

Object_attribute*

Vendor_object_attributes::get_attribute(int tag)

{

  if (tag < NUM_KNOWN_ATTRIBUTES)

    return &this->known_attributes_[tag];

  else

    {

      Other_attributes::iterator p =

        this->other_attributes_.find(tag);

      return p != this->other_attributes_.end() ? p->second : NULL;

    }

}

const Object_attribute*

Vendor_object_attributes::get_attribute(int tag) const

{

  if (tag < NUM_KNOWN_ATTRIBUTES)

    return &this->known_attributes_[tag];

  else

    {

      Other_attributes::const_iterator p =

        this->other_attributes_.find(tag);

      return p != this->other_attributes_.end() ? p->second : NULL;

    }

}

// Write attributes to BUFFER.

void

Vendor_object_attributes::write(std::vector<unsigned char>* buffer) const

{

  // Write subsection size.

  size_t voa_size = this->size();

  uint32_t voa_size_as_u32 = convert_types<uint32_t, size_t>(voa_size);

  insert_into_vector<32>(buffer, voa_size_as_u32);

  // Write vendor name.

  const unsigned char* vendor_start =

    reinterpret_cast<const unsigned char*>(this->name());

  size_t vendor_length = strlen(this->name()) + 1;

  const unsigned char* vendor_end = vendor_start + vendor_length;

  buffer->insert(buffer->end(), vendor_start, vendor_end);

  // Write file tag.

  buffer->push_back(Object_attribute::Tag_File);

  // Write attributes size.

  uint32_t attributes_size_as_u32 =

    convert_types<uint32_t, size_t>(voa_size - 4 - vendor_length);

  insert_into_vector<32>(buffer, attributes_size_as_u32);

  // Write known attributes, skipping any defaults.

  for (int i = 4; i < NUM_KNOWN_ATTRIBUTES; ++i)

    {

      // A target may write known attributes in a special order. 

      // Call target hook to remap tags.  Attributes_order is the identity

      // function if no re-ordering is required.

      int tag = parameters->target().attributes_order(i);

      this->known_attributes_[tag].write(tag, buffer);

    }

  // Write other attributes.

  for (Other_attributes::const_iterator q = this->other_attributes_.begin();

       q != this->other_attributes_.end();

       ++q)

    q->second->write(q->first, buffer);

}

// Attributes_section_data methods.

// Compute encoded size of this.

size_t

Attributes_section_data::size() const

{

  size_t data_size = 0;

  for(int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)

    data_size += this->vendor_object_attributes_[vendor]->size();

  // 'A' <sections for each vendor>

  return data_size != 0 ? data_size + 1 : 0;

}

// Construct an Attributes_section_data object by parsing section contents

// specified by VIEW and SIZE.

Attributes_section_data::Attributes_section_data(

    const unsigned char* view,

    section_size_type size)

{

  for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)

    this->vendor_object_attributes_[vendor] =

      new Vendor_object_attributes(vendor);

  const unsigned char* p = view;

  p = view;

  if (size > 0 && p != NULL && *(p++) == 'A')

    {

      size--;

      while (size > 0)

        {

          // Size of vendor attributes section.

          section_size_type section_size =

            convert_to_section_size_type(read_from_pointer<32>(&p));

          if (section_size > size)

            section_size = size;

          size -= section_size;

          const char* section_name = reinterpret_cast<const char*>(p);

          section_size_type section_name_size = strlen(section_name) + 1;

          section_size -= section_name_size + 4;

          int vendor;

          const char* std_section = parameters->target().attributes_vendor();

          if (std_section != NULL && strcmp(section_name, std_section) == 0)

            vendor = Object_attribute::OBJ_ATTR_PROC;

          else if (strcmp(section_name, "gnu") == 0)

            vendor = Object_attribute::OBJ_ATTR_GNU;

          else

            {

              // Other vendor section.  Ignore it.

              p += section_name_size + section_size;

              continue;

            }

          p += section_name_size;

          while (section_size > 0)

            {

              const unsigned char* subsection_start = p;

              // Read vendor subsection index and size.

              size_t uleb128_len;

              uint64_t val = read_unsigned_LEB_128(p, &uleb128_len);

              p += uleb128_len;

              int tag = convert_types<int, uint64_t>(val);

              section_size_type subsection_size =

                convert_to_section_size_type(read_from_pointer<32>(&p));

              section_size -= subsection_size;

              subsection_size -= (p - subsection_start);

              const unsigned char* end = p + subsection_size;

              switch (tag)

                {

                case Object_attribute::Tag_File:

                  while (p < end)

                    {

                      val = read_unsigned_LEB_128(p, &uleb128_len);

                      p += uleb128_len;

                      tag = convert_types<int, uint64_t>(val);

                      Vendor_object_attributes* pvoa =

                        this->vendor_object_attributes_[vendor];

                      Object_attribute* attr = pvoa->new_attribute(tag);

                      const char* string_arg;

                      unsigned int int_arg;

                      int type = Object_attribute::arg_type(vendor, tag);

                      switch (type

                              & (Object_attribute::ATTR_TYPE_FLAG_INT_VAL

                                 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL))

                        {

                        case (Object_attribute::ATTR_TYPE_FLAG_INT_VAL

                              | Object_attribute::ATTR_TYPE_FLAG_STR_VAL):

                          val = read_unsigned_LEB_128(p, &uleb128_len);

                          p += uleb128_len;

                          int_arg = convert_types<unsigned int, uint64_t>(val);

                          string_arg = reinterpret_cast<const char *>(p);

                          attr->set_int_value(int_arg);

                          p += strlen(string_arg) + 1;

                          break;

                        case Object_attribute::ATTR_TYPE_FLAG_STR_VAL:

                          string_arg = reinterpret_cast<const char *>(p);

                          attr->set_string_value(string_arg);

                          p += strlen(string_arg) + 1;

                          break;

                        case Object_attribute::ATTR_TYPE_FLAG_INT_VAL:

                          val = read_unsigned_LEB_128(p, &uleb128_len);

                          p += uleb128_len;

                          int_arg = convert_types<unsigned int, uint64_t>(val);

                          attr->set_int_value(int_arg);

                          break;

                        default:

                          gold_unreachable();

                        }

                    }

                  break;

                case Object_attribute::Tag_Section:

                case Object_attribute::Tag_Symbol:

                  // Don't have anywhere convenient to attach these.

                  // Fall through for now.

                default:

                  // Ignore things we don't know about.

                  p += subsection_size;

                  subsection_size = 0;

                  break;

                }

            }

        }

    }

}

// Merge target-independent attributes from another Attribute_section_data

// ASD from an object called NAME into this.

void

Attributes_section_data::merge(

    const char* name,

    const Attributes_section_data* pasd)

{

  // The only common attribute is currently Tag_compatibility,

  // accepted in both processor and "gnu" sections.

  for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)

    {

      // Handle Tag_compatibility.  The tags are only compatible if the flags

      // are identical and, if the flags are '1', the strings are identical.

      // If the flags are non-zero, then we can only use the string "gnu".

      const Object_attribute* in_attr =

        &pasd->known_attributes(vendor)[Object_attribute::Tag_compatibility];

      Object_attribute* out_attr =

        &this->known_attributes(vendor)[Object_attribute::Tag_compatibility];

      if (in_attr->int_value() > 0

          && in_attr->string_value() != "gnu")

        {

          gold_error(_("%s: must be processed by '%s' toolchain"),

                     name, in_attr->string_value().c_str());

          return;

        }

      if (in_attr->int_value() != out_attr->int_value()

          || in_attr->string_value() != out_attr->string_value())

        {

          gold_error(_("%s: object tag '%d, %s' is "

                       "incompatible with tag '%d, %s'"),

                     name, in_attr->int_value(),

                     in_attr->string_value().c_str(),

                     out_attr->int_value(),

                     out_attr->string_value().c_str());

        }

    }

}

// Write to a buffer.

void

Attributes_section_data::write(std::vector<unsigned char>* buffer) const

{

  buffer->push_back('A');

  for (int vendor = OBJ_ATTR_FIRST; vendor <= OBJ_ATTR_LAST; ++vendor)

    if (this->vendor_object_attributes_[vendor]->size() != 0)

      this->vendor_object_attributes_[vendor]->write(buffer);

}

// Methods for Output_attributes_section_data.

// Write attributes section data to file OF.

void

Output_attributes_section_data::do_write(Output_file* of)

{

  off_t offset = this->offset();

  const section_size_type oview_size =

    convert_to_section_size_type(this->data_size());

  unsigned char* const oview = of->get_output_view(offset, oview_size);

  std::vector<unsigned char> buffer;

  this->attributes_section_data_.write(&buffer);

  gold_assert(convert_to_section_size_type(buffer.size()) == oview_size);

  memcpy(oview, &buffer.front(), buffer.size());

  of->write_output_view(this->offset(), oview_size, oview);

}

} // End namespace gold.