nasm/output/outelf.c

/* ----------------------------------------------------------------------- *
 *   
 *   Copyright 1996-2014 The NASM Authors - All Rights Reserved
 *   See the file AUTHORS included with the NASM distribution for
 *   the specific copyright holders.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following
 *   conditions are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * 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 COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
 *
 * ----------------------------------------------------------------------- */

/*
 * Common code for outelf32 and outelf64
 */

#include "compiler.h"

#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>

#include "nasm.h"
#include "output/outform.h"

#include "output/dwarf.h"
#include "output/elf.h"
#include "output/outelf.h"

#if defined(OF_ELF32) || defined(OF_ELF64) || defined(OF_ELFX32)

uint8_t elf_osabi = 0;      /* Default OSABI = 0 (System V or Linux) */
uint8_t elf_abiver = 0;     /* Current ABI version */

const struct elf_known_section elf_known_sections[] = {
    { ".text",    SHT_PROGBITS, SHF_ALLOC|SHF_EXECINSTR,     16 },
    { ".rodata",  SHT_PROGBITS, SHF_ALLOC,                    4 },
    { ".lrodata", SHT_PROGBITS, SHF_ALLOC,                    4 },
    { ".data",    SHT_PROGBITS, SHF_ALLOC|SHF_WRITE,          4 },
    { ".ldata",   SHT_PROGBITS, SHF_ALLOC|SHF_WRITE,          4 },
    { ".bss",     SHT_NOBITS,   SHF_ALLOC|SHF_WRITE,          4 },
    { ".lbss",    SHT_NOBITS,   SHF_ALLOC|SHF_WRITE,          4 },
    { ".tdata",   SHT_PROGBITS, SHF_ALLOC|SHF_WRITE|SHF_TLS,  4 },
    { ".tbss",    SHT_NOBITS,   SHF_ALLOC|SHF_WRITE|SHF_TLS,  4 },
    { ".comment", SHT_PROGBITS, 0,                            1 },
    { NULL,       SHT_PROGBITS, SHF_ALLOC,                    1 } /* default */
};

/* parse section attributes */
void elf_section_attrib(char *name, char *attr, int pass,
			uint32_t *flags_and, uint32_t *flags_or,
			uint64_t *align, int *type)
{
    char *opt, *val, *next;

    opt = nasm_skip_spaces(attr);
    if (!opt || !*opt)
        return;

    while ((opt = nasm_opt_val(opt, &val, &next))) {
        if (!nasm_stricmp(opt, "align")) {
            if (!val) {
                nasm_error(ERR_NONFATAL,
                           "section align without value specified");
            } else {
                *align = atoi(val);
                if (*align == 0) {
                    *align = SHA_ANY;
                } else if (!is_power2(*align)) {
                    nasm_error(ERR_NONFATAL,
                               "section alignment %"PRId64" is not a power of two",
                               *align);
                    *align = SHA_ANY;
                }
            }
        } else if (!nasm_stricmp(opt, "alloc")) {
            *flags_and  |= SHF_ALLOC;
            *flags_or   |= SHF_ALLOC;
        } else if (!nasm_stricmp(opt, "noalloc")) {
            *flags_and  |= SHF_ALLOC;
            *flags_or   &= ~SHF_ALLOC;
        } else if (!nasm_stricmp(opt, "exec")) {
            *flags_and  |= SHF_EXECINSTR;
            *flags_or   |= SHF_EXECINSTR;
        } else if (!nasm_stricmp(opt, "noexec")) {
            *flags_and  |= SHF_EXECINSTR;
            *flags_or   &= ~SHF_EXECINSTR;
        } else if (!nasm_stricmp(opt, "write")) {
            *flags_and  |= SHF_WRITE;
            *flags_or   |= SHF_WRITE;
        } else if (!nasm_stricmp(opt, "tls")) {
            *flags_and  |= SHF_TLS;
            *flags_or   |= SHF_TLS;
        } else if (!nasm_stricmp(opt, "nowrite")) {
            *flags_and  |= SHF_WRITE;
            *flags_or   &= ~SHF_WRITE;
        } else if (!nasm_stricmp(opt, "progbits")) {
            *type = SHT_PROGBITS;
        } else if (!nasm_stricmp(opt, "nobits")) {
            *type = SHT_NOBITS;
        } else if (pass == 1) {
            nasm_error(ERR_WARNING,
                       "Unknown section attribute '%s' ignored on"
                       " declaration of section `%s'", opt, name);
        }
        opt = next;
    }
}

int elf_directive(enum directives directive, char *value, int pass)
{
    int64_t n;
    bool err;
    char *p;

    switch (directive) {
    case D_OSABI:
        if (pass == 2)
            return 1; /* ignore in pass 2 */

        n = readnum(value, &err);
        if (err) {
            nasm_error(ERR_NONFATAL, "`osabi' directive requires a parameter");
            return 1;
        }

        if (n < 0 || n > 255) {
            nasm_error(ERR_NONFATAL, "valid osabi numbers are 0 to 255");
            return 1;
        }

        elf_osabi  = n;
        elf_abiver = 0;

        p = strchr(value,',');
        if (!p)
            return 1;

        n = readnum(p + 1, &err);
        if (err || n < 0 || n > 255) {
            nasm_error(ERR_NONFATAL, "invalid ABI version number (valid: 0 to 255)");
            return 1;
        }

        elf_abiver = n;
        return 1;

    default:
        return 0;
    }
}

#endif /* defined(OF_ELF32) || defined(OF_ELF64) || defined(OF_ELFX32) */