output/outelf.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1996-2014 The NASM Authors - All Rights Reserved
   4  *   See the file AUTHORS included with the NASM distribution for
   5  *   the specific copyright holders.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following
   9  *   conditions are met:
  10  *
  11  *   * Redistributions of source code must retain the above copyright
  12  *     notice, this list of conditions and the following disclaimer.
  13  *   * Redistributions in binary form must reproduce the above
  14  *     copyright notice, this list of conditions and the following
  15  *     disclaimer in the documentation and/or other materials provided
  16  *     with the distribution.
  17  *
  18  *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  19  *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  20  *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  21  *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  22  *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  23  *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24  *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  26  *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  29  *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
  30  *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * ----------------------------------------------------------------------- */
  33
  34 /*
  35  * Common code for outelf32 and outelf64
  36  */
  37
  38 #include "compiler.h"
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <inttypes.h>
  43
  44 #include "nasm.h"
  45 #include "output/outform.h"
  46
  47 #include "output/dwarf.h"
  48 #include "output/elf.h"
  49 #include "output/outelf.h"
  50
  51 #if defined(OF_ELF32) || defined(OF_ELF64) || defined(OF_ELFX32)
  52
  53 uint8_t elf_osabi = 0;      /* Default OSABI = 0 (System V or Linux) */
  54 uint8_t elf_abiver = 0;     /* Current ABI version */
  55
  56 const struct elf_known_section elf_known_sections[] = {
  57     { ".text",    SHT_PROGBITS, SHF_ALLOC|SHF_EXECINSTR,     16 },
  58     { ".rodata",  SHT_PROGBITS, SHF_ALLOC,                    4 },
  59     { ".lrodata", SHT_PROGBITS, SHF_ALLOC,                    4 },
  60     { ".data",    SHT_PROGBITS, SHF_ALLOC|SHF_WRITE,          4 },
  61     { ".ldata",   SHT_PROGBITS, SHF_ALLOC|SHF_WRITE,          4 },
  62     { ".bss",     SHT_NOBITS,   SHF_ALLOC|SHF_WRITE,          4 },
  63     { ".lbss",    SHT_NOBITS,   SHF_ALLOC|SHF_WRITE,          4 },
  64     { ".tdata",   SHT_PROGBITS, SHF_ALLOC|SHF_WRITE|SHF_TLS,  4 },
  65     { ".tbss",    SHT_NOBITS,   SHF_ALLOC|SHF_WRITE|SHF_TLS,  4 },
  66     { ".comment", SHT_PROGBITS, 0,                            1 },
  67     { NULL,       SHT_PROGBITS, SHF_ALLOC,                    1 } /* default */
  68 };
  69
  70 /* parse section attributes */
  71 void elf_section_attrib(char *name, char *attr, int pass,
  72                         uint32_t *flags_and, uint32_t *flags_or,
  73                         uint64_t *align, int *type)
  74 {
  75     char *opt, *val, *next;
  76
  77     opt = nasm_skip_spaces(attr);
  78     if (!opt || !*opt)
  79         return;
  80
  81     while ((opt = nasm_opt_val(opt, &val, &next))) {
  82         if (!nasm_stricmp(opt, "align")) {
  83             if (!val) {
  84                 nasm_error(ERR_NONFATAL,
  85                            "section align without value specified");
  86             } else {
  87                 *align = atoi(val);
  88                 if (*align == 0) {
  89                     *align = SHA_ANY;
  90                 } else if (!is_power2(*align)) {
  91                     nasm_error(ERR_NONFATAL,
  92                                "section alignment %"PRId64" is not a power of two",
  93                                *align);
  94                     *align = SHA_ANY;
  95                 }
  96             }
  97         } else if (!nasm_stricmp(opt, "alloc")) {
  98             *flags_and  |= SHF_ALLOC;
  99             *flags_or   |= SHF_ALLOC;
 100         } else if (!nasm_stricmp(opt, "noalloc")) {
 101             *flags_and  |= SHF_ALLOC;
 102             *flags_or   &= ~SHF_ALLOC;
 103         } else if (!nasm_stricmp(opt, "exec")) {
 104             *flags_and  |= SHF_EXECINSTR;
 105             *flags_or   |= SHF_EXECINSTR;
 106         } else if (!nasm_stricmp(opt, "noexec")) {
 107             *flags_and  |= SHF_EXECINSTR;
 108             *flags_or   &= ~SHF_EXECINSTR;
 109         } else if (!nasm_stricmp(opt, "write")) {
 110             *flags_and  |= SHF_WRITE;
 111             *flags_or   |= SHF_WRITE;
 112         } else if (!nasm_stricmp(opt, "tls")) {
 113             *flags_and  |= SHF_TLS;
 114             *flags_or   |= SHF_TLS;
 115         } else if (!nasm_stricmp(opt, "nowrite")) {
 116             *flags_and  |= SHF_WRITE;
 117             *flags_or   &= ~SHF_WRITE;
 118         } else if (!nasm_stricmp(opt, "progbits")) {
 119             *type = SHT_PROGBITS;
 120         } else if (!nasm_stricmp(opt, "nobits")) {
 121             *type = SHT_NOBITS;
 122         } else if (pass == 1) {
 123             nasm_error(ERR_WARNING,
 124                        "Unknown section attribute '%s' ignored on"
 125                        " declaration of section `%s'", opt, name);
 126         }
 127         opt = next;
 128     }
 129 }
 130
 131 int elf_directive(enum directives directive, char *value, int pass)
 132 {
 133     int64_t n;
 134     bool err;
 135     char *p;
 136
 137     switch (directive) {
 138     case D_OSABI:
 139         if (pass == 2)
 140             return 1; /* ignore in pass 2 */
 141
 142         n = readnum(value, &err);
 143         if (err) {
 144             nasm_error(ERR_NONFATAL, "`osabi' directive requires a parameter");
 145             return 1;
 146         }
 147
 148         if (n < 0 || n > 255) {
 149             nasm_error(ERR_NONFATAL, "valid osabi numbers are 0 to 255");
 150             return 1;
 151         }
 152
 153         elf_osabi  = n;
 154         elf_abiver = 0;
 155
 156         p = strchr(value,',');
 157         if (!p)
 158             return 1;
 159
 160         n = readnum(p + 1, &err);
 161         if (err || n < 0 || n > 255) {
 162             nasm_error(ERR_NONFATAL, "invalid ABI version number (valid: 0 to 255)");
 163             return 1;
 164         }
 165
 166         elf_abiver = n;
 167         return 1;
 168
 169     default:
 170         return 0;
 171     }
 172 }
 173
 174 #endif /* defined(OF_ELF32) || defined(OF_ELF64) || defined(OF_ELFX32) */