/*-
 * Copyright (c) 2006,2008 Joseph Koshy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>

#include <libelf.h>

#include "_libelf.h"

ELFTC_VCSID("$Id: libelf_align.c,v 1.1 2019/02/01 05:27:38 jsg Exp $");

struct align {
        unsigned int a32;
        unsigned int a64;
};

#ifdef  __GNUC__
#define MALIGN(N)       {                                       \
                .a32 = __alignof__(Elf32_##N),                  \
                .a64 = __alignof__(Elf64_##N)                   \
        }
#define MALIGN64(V)       {                                     \
                .a32 = 0,                                       \
                .a64 = __alignof__(Elf64_##V)                   \
        }
#define MALIGN_WORD()   {                                       \
                .a32 = __alignof__(int32_t),                    \
                .a64 = __alignof__(int64_t)                     \
            }
#else
#error  Need the __alignof__ builtin.
#endif
#define UNSUPPORTED()   {                                       \
                .a32 = 0,                                       \
                .a64 = 0                                        \
        }

static struct align malign[ELF_T_NUM] = {
        [ELF_T_ADDR]    = MALIGN(Addr),
        [ELF_T_BYTE]    = { .a32 = 1, .a64 = 1 },
        [ELF_T_CAP]     = MALIGN(Cap),
        [ELF_T_DYN]     = MALIGN(Dyn),
        [ELF_T_EHDR]    = MALIGN(Ehdr),
        [ELF_T_HALF]    = MALIGN(Half),
        [ELF_T_LWORD]   = MALIGN(Lword),
        [ELF_T_MOVE]    = MALIGN(Move),
        [ELF_T_MOVEP]   = UNSUPPORTED(),
        [ELF_T_NOTE]    = MALIGN(Nhdr),
        [ELF_T_OFF]     = MALIGN(Off),
        [ELF_T_PHDR]    = MALIGN(Phdr),
        [ELF_T_REL]     = MALIGN(Rel),
        [ELF_T_RELA]    = MALIGN(Rela),
        [ELF_T_SHDR]    = MALIGN(Shdr),
        [ELF_T_SWORD]   = MALIGN(Sword),
        [ELF_T_SXWORD]  = MALIGN64(Sxword),
        [ELF_T_SYM]     = MALIGN(Sym),
        [ELF_T_SYMINFO] = MALIGN(Syminfo),
        [ELF_T_VDEF]    = MALIGN(Verdef),
        [ELF_T_VNEED]   = MALIGN(Verneed),
        [ELF_T_WORD]    = MALIGN(Word),
        [ELF_T_XWORD]   = MALIGN64(Xword),
        [ELF_T_GNUHASH] = MALIGN_WORD()
};

unsigned int
_libelf_malign(Elf_Type t, int elfclass)
{
        if (t >= ELF_T_NUM || (int) t < 0)
                return (0);

        return (elfclass == ELFCLASS32 ? malign[t].a32 :
            malign[t].a64);
}

#define FALIGN(A32,A64) { .a32 = (A32), .a64 = (A64) }

static struct align falign[ELF_T_NUM] = {
        [ELF_T_ADDR]    = FALIGN(4,8),
        [ELF_T_BYTE]    = FALIGN(1,1),
        [ELF_T_CAP]     = FALIGN(4,8),
        [ELF_T_DYN]     = FALIGN(4,8),
        [ELF_T_EHDR]    = FALIGN(4,8),
        [ELF_T_HALF]    = FALIGN(2,2),
        [ELF_T_LWORD]   = FALIGN(8,8),
        [ELF_T_MOVE]    = FALIGN(8,8),
        [ELF_T_MOVEP]   = UNSUPPORTED(),
        [ELF_T_NOTE]    = FALIGN(4,4),
        [ELF_T_OFF]     = FALIGN(4,8),
        [ELF_T_PHDR]    = FALIGN(4,8),
        [ELF_T_REL]     = FALIGN(4,8),
        [ELF_T_RELA]    = FALIGN(4,8),
        [ELF_T_SHDR]    = FALIGN(4,8),
        [ELF_T_SWORD]   = FALIGN(4,4),
        [ELF_T_SXWORD]  = FALIGN(0,8),
        [ELF_T_SYM]     = FALIGN(4,8),
        [ELF_T_SYMINFO] = FALIGN(2,2),
        [ELF_T_VDEF]    = FALIGN(4,4),
        [ELF_T_VNEED]   = FALIGN(4,4),
        [ELF_T_WORD]    = FALIGN(4,4),
        [ELF_T_XWORD]   = FALIGN(0,8),
        [ELF_T_GNUHASH] = FALIGN(4,8)
};

unsigned int
_libelf_falign(Elf_Type t, int elfclass)
{
        if (t >= ELF_T_NUM || (int) t < 0)
                return (0);

        return (elfclass == ELFCLASS32 ? falign[t].a32 :
            falign[t].a64);
}