Subversion Repositories open8_urisc

/* plugin_section_reorder.c -- Simple plugin to reorder function sections

   Copyright 2011 Free Software Foundation, Inc.

   Written by Sriraman Tallam <tmsriram@google.com>.

   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.  */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <assert.h>

#include "plugin-api.h"

static ld_plugin_get_input_section_count get_input_section_count = NULL;

static ld_plugin_get_input_section_type get_input_section_type = NULL;

static ld_plugin_get_input_section_name get_input_section_name = NULL;

static ld_plugin_get_input_section_contents get_input_section_contents = NULL;

static ld_plugin_update_section_order update_section_order = NULL;

static ld_plugin_allow_section_ordering allow_section_ordering = NULL;

enum ld_plugin_status onload(struct ld_plugin_tv *tv);

enum ld_plugin_status claim_file_hook(const struct ld_plugin_input_file *file,

                                      int *claimed);

enum ld_plugin_status all_symbols_read_hook(void);

/* Plugin entry point.  */

enum ld_plugin_status

onload(struct ld_plugin_tv *tv)

{

  struct ld_plugin_tv *entry;

  for (entry = tv; entry->tv_tag != LDPT_NULL; ++entry)

    {

      switch (entry->tv_tag)

        {

        case LDPT_REGISTER_CLAIM_FILE_HOOK:

          assert((*entry->tv_u.tv_register_claim_file) (claim_file_hook) == LDPS_OK);

          break;

        case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:

          assert((*entry->tv_u.tv_register_all_symbols_read) (all_symbols_read_hook)

                  == LDPS_OK);

          break;

        case LDPT_GET_INPUT_SECTION_COUNT:

          get_input_section_count = *entry->tv_u.tv_get_input_section_count;

          break;

        case LDPT_GET_INPUT_SECTION_TYPE:

          get_input_section_type = *entry->tv_u.tv_get_input_section_type;

          break;

        case LDPT_GET_INPUT_SECTION_NAME:

          get_input_section_name = *entry->tv_u.tv_get_input_section_name;

          break;

        case LDPT_GET_INPUT_SECTION_CONTENTS:

          get_input_section_contents = *entry->tv_u.tv_get_input_section_contents;

          break;

        case LDPT_UPDATE_SECTION_ORDER:

          update_section_order = *entry->tv_u.tv_update_section_order;

          break;

        case LDPT_ALLOW_SECTION_ORDERING:

          allow_section_ordering = *entry->tv_u.tv_allow_section_ordering;

          break;

        default:

          break;

        }

    }

  if (get_input_section_count == NULL

      || get_input_section_type == NULL

      || get_input_section_name == NULL

      || get_input_section_contents == NULL

      || update_section_order == NULL

      || allow_section_ordering == NULL)

    {

      fprintf(stderr, "Some interfaces are missing\n");

      return LDPS_ERR;

    }

  return LDPS_OK;

}

inline static int is_prefix_of(const char *prefix, const char *str)

{

  return strncmp(prefix, str, strlen (prefix)) == 0;

}

struct ld_plugin_section section_list[3];

int num_entries = 0;

/* This function is called by the linker for every new object it encounters.  */

enum ld_plugin_status

claim_file_hook(const struct ld_plugin_input_file *file, int *claimed)

{

  static int is_ordering_specified = 0;

  struct ld_plugin_section section;

  unsigned int count = 0;

  unsigned int shndx;

  *claimed = 0;

  if (is_ordering_specified == 0)

    {

      /* Inform the linker to prepare for section reordering.  */

      (*allow_section_ordering)();

      is_ordering_specified = 1;

    }

  (*get_input_section_count)(file->handle, &count);

  for (shndx = 0; shndx < count; ++shndx)

    {

      char *name = NULL;

      int position = 3;

      section.handle = file->handle;

      section.shndx = shndx;

      (*get_input_section_name)(section, &name);

      /* Order is foo() followed by bar() followed by baz()  */

      if (is_prefix_of(".text.", name))

        {

          if (strstr(name, "_Z3foov") != NULL)

            position = 0;

          else if (strstr(name, "_Z3barv") != NULL)

            position = 1;

          else if (strstr(name, "_Z3bazv") != NULL)

            position = 2;

          else

            position = 3;

        }

      if (position < 3)

        {

          section_list[position].handle = file->handle;

          section_list[position].shndx = shndx;

          num_entries++;

        }

    }

  return LDPS_OK;

}

/* This function is called by the linker after all the symbols have been read.

   At this stage, it is fine to tell the linker the desired function order.  */

enum ld_plugin_status

all_symbols_read_hook(void)

{

  if (num_entries == 3)

    update_section_order(section_list, num_entries);

  return LDPS_OK;

}