/*

opt.delscn.c - implementation of the elf_delscn(3) function.

Copyright (C) 1995 - 2001 Michael Riepe

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Library General Public

License as published by the Free Software Foundation; either

version 2 of the License, or (at your option) any later version.

This library 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

Library General Public License for more details.

You should have received a copy of the GNU Library General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

#include <private.h>

#ifndef lint

static const char rcsid[] = "@(#) $Id: opt.delscn.c,v 1.11 2005/05/21 15:39:25 michael Exp $";

#endif /* lint */

static size_t

_newindex(size_t old, size_t index) {

    return old == index ? SHN_UNDEF : (old > index ? old - 1 : old);

}

static void

_elf32_update_shdr(Elf *elf, size_t index) {

    Elf32_Shdr *shdr;

    Elf_Scn *scn;

    ((Elf32_Ehdr*)elf->e_ehdr)->e_shnum = elf->e_scn_n->s_index + 1;

    for (scn = elf->e_scn_1; scn; scn = scn->s_link) {

	shdr = &scn->s_shdr32;

	switch (shdr->sh_type) {

	    case SHT_REL:

	    case SHT_RELA:

		shdr->sh_info = _newindex(shdr->sh_info, index);

		/* fall through */

	    case SHT_DYNSYM:

	    case SHT_DYNAMIC:

	    case SHT_HASH:

	    case SHT_SYMTAB:

#if __LIBELF_SYMBOL_VERSIONS

#if __LIBELF_SUN_SYMBOL_VERSIONS

	    case SHT_SUNW_verdef:

	    case SHT_SUNW_verneed:

	    case SHT_SUNW_versym:

#else /* __LIBELF_SUN_SYMBOL_VERSIONS */

	    case SHT_GNU_verdef:

	    case SHT_GNU_verneed:

	    case SHT_GNU_versym:

#endif /* __LIBELF_SUN_SYMBOL_VERSIONS */

#endif /* __LIBELF_SYMBOL_VERSIONS */

		shdr->sh_link = _newindex(shdr->sh_link, index);

		/* fall through */

	    default:

		break;

	}

    }

}

#if __LIBELF64

static void

_elf64_update_shdr(Elf *elf, size_t index) {

    Elf64_Shdr *shdr;

    Elf_Scn *scn;

    ((Elf64_Ehdr*)elf->e_ehdr)->e_shnum = elf->e_scn_n->s_index + 1;

    for (scn = elf->e_scn_1; scn; scn = scn->s_link) {

	shdr = &scn->s_shdr64;

	switch (shdr->sh_type) {

	    case SHT_REL:

	    case SHT_RELA:

		shdr->sh_info = _newindex(shdr->sh_info, index);

		/* fall through */

	    case SHT_DYNSYM:

	    case SHT_DYNAMIC:

	    case SHT_HASH:

	    case SHT_SYMTAB:

#if __LIBELF_SYMBOL_VERSIONS

#if __LIBELF_SUN_SYMBOL_VERSIONS

	    case SHT_SUNW_verdef:

	    case SHT_SUNW_verneed:

	    case SHT_SUNW_versym:

#else /* __LIBELF_SUN_SYMBOL_VERSIONS */

	    case SHT_GNU_verdef:

	    case SHT_GNU_verneed:

	    case SHT_GNU_versym:

#endif /* __LIBELF_SUN_SYMBOL_VERSIONS */

#endif /* __LIBELF_SYMBOL_VERSIONS */

		shdr->sh_link = _newindex(shdr->sh_link, index);

		/* fall through */

	    default:

		break;

	}

    }

}

#endif /* __LIBELF64 */

size_t

elf_delscn(Elf *elf, Elf_Scn *scn) {

    Elf_Scn *pscn;

    Scn_Data *sd;

    Scn_Data *tmp;

    size_t index;

    if (!elf || !scn) {

	return SHN_UNDEF;

    }

    elf_assert(elf->e_magic == ELF_MAGIC);

    elf_assert(scn->s_magic == SCN_MAGIC);

    elf_assert(elf->e_ehdr);

    if (scn->s_elf != elf) {

	seterr(ERROR_ELFSCNMISMATCH);

	return SHN_UNDEF;

    }

    elf_assert(elf->e_scn_1);

    if (scn == elf->e_scn_1) {

	seterr(ERROR_NULLSCN);

	return SHN_UNDEF;

    }

    /*

     * Find previous section.

     */

    for (pscn = elf->e_scn_1; pscn->s_link; pscn = pscn->s_link) {

	if (pscn->s_link == scn) {

	    break;

	}

    }

    if (pscn->s_link != scn) {

	seterr(ERROR_ELFSCNMISMATCH);

	return SHN_UNDEF;

    }

    /*

     * Unlink section.

     */

    if (elf->e_scn_n == scn) {

	elf->e_scn_n = pscn;

    }

    pscn->s_link = scn->s_link;

    index = scn->s_index;

    /*

     * Free section descriptor and data.

     */

    for (sd = scn->s_data_1; sd; sd = tmp) {

	elf_assert(sd->sd_magic == DATA_MAGIC);

	elf_assert(sd->sd_scn == scn);

	tmp = sd->sd_link;

	if (sd->sd_free_data && sd->sd_memdata) {

	    free(sd->sd_memdata);

	}

	if (sd->sd_freeme) {

	    free(sd);

	}

    }

    if ((sd = scn->s_rawdata)) {

	elf_assert(sd->sd_magic == DATA_MAGIC);

	elf_assert(sd->sd_scn == scn);

	if (sd->sd_free_data && sd->sd_memdata) {

	    free(sd->sd_memdata);

	}

	if (sd->sd_freeme) {

	    free(sd);

	}

    }

    if (scn->s_freeme) {

	elf_assert(scn->s_index > 0);

	free(scn);

    }

    /*

     * Adjust section indices.

     */

    for (scn = pscn->s_link; scn; scn = scn->s_link) {

	elf_assert(scn->s_index > index);

	scn->s_index--;

    }

    /*

     * Adjust ELF header and well-known section headers.

     */

    if (elf->e_class == ELFCLASS32) {

	_elf32_update_shdr(elf, index);

	return index;

    }

#if __LIBELF64

    else if (elf->e_class == ELFCLASS64) {

	_elf64_update_shdr(elf, index);

	return index;

    }

#endif /* __LIBELF64 */

    else if (valid_class(elf->e_class)) {

	seterr(ERROR_UNIMPLEMENTED);

    }

    else {

	seterr(ERROR_UNKNOWN_CLASS);

    }

    return SHN_UNDEF;

}