root/trunk/src/recompiler/dyngen.c

/*
 *  Generic Dynamic compiler generator
 * 
 *  Copyright (c) 2003 Fabrice Bellard
 *
 *  The COFF object format support was extracted from Kazu's QEMU port
 *  to Win32.
 *
 *  Mach-O Support by Matt Reda and Pierre d'Herbemont
 *
 *  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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * Sun GPL Disclaimer: For the avoidance of doubt, except that if any license choice
 * other than GPL or LGPL is available it will apply instead, Sun elects to use only
 * the General Public License version 2 (GPLv2) at this time for any software where
 * a choice of GPL license versions is made available with the language indicating
 * that GPLv2 or any later version may be used, or where a choice of which version
 * of the GPL is applied is otherwise unspecified.
 */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <inttypes.h>
#include <unistd.h>
#include <fcntl.h>

#include "config-host.h"

/* NOTE: we test CONFIG_WIN32 instead of _WIN32 to enabled cross
   compilation */
#if defined(CONFIG_WIN32)
#define CONFIG_FORMAT_COFF
#elif defined(CONFIG_DARWIN)
#define CONFIG_FORMAT_MACH
#elif defined(CONFIG_OS2)
#define CONFIG_FORMAT_AOUT
#else
#define CONFIG_FORMAT_ELF
#endif

#ifdef CONFIG_FORMAT_ELF

/* elf format definitions. We use these macros to test the CPU to
   allow cross compilation (this tool must be ran on the build
   platform) */
#if defined(HOST_I386)

#define ELF_CLASS       ELFCLASS32
#define ELF_ARCH        EM_386
#define elf_check_arch(x) ( ((x) == EM_386) || ((x) == EM_486) )
#undef ELF_USES_RELOCA

#elif defined(HOST_X86_64)

#define ELF_CLASS       ELFCLASS64
#define ELF_ARCH        EM_X86_64
#define elf_check_arch(x) ((x) == EM_X86_64)
#define ELF_USES_RELOCA

#elif defined(HOST_PPC)

#define ELF_CLASS       ELFCLASS32
#define ELF_ARCH        EM_PPC
#define elf_check_arch(x) ((x) == EM_PPC)
#define ELF_USES_RELOCA

#elif defined(HOST_S390)

#define ELF_CLASS       ELFCLASS32
#define ELF_ARCH        EM_S390
#define elf_check_arch(x) ((x) == EM_S390)
#define ELF_USES_RELOCA

#elif defined(HOST_ALPHA)

#define ELF_CLASS       ELFCLASS64
#define ELF_ARCH        EM_ALPHA
#define elf_check_arch(x) ((x) == EM_ALPHA)
#define ELF_USES_RELOCA

#elif defined(HOST_IA64)

#define ELF_CLASS       ELFCLASS64
#define ELF_ARCH        EM_IA_64
#define elf_check_arch(x) ((x) == EM_IA_64)
#define ELF_USES_RELOCA

#elif defined(HOST_SPARC)

#define ELF_CLASS       ELFCLASS32
#define ELF_ARCH        EM_SPARC
#define elf_check_arch(x) ((x) == EM_SPARC || (x) == EM_SPARC32PLUS)
#define ELF_USES_RELOCA

#elif defined(HOST_SPARC64)

#define ELF_CLASS       ELFCLASS64
#define ELF_ARCH        EM_SPARCV9
#define elf_check_arch(x) ((x) == EM_SPARCV9)
#define ELF_USES_RELOCA

#elif defined(HOST_ARM)

#define ELF_CLASS       ELFCLASS32
#define ELF_ARCH        EM_ARM
#define elf_check_arch(x) ((x) == EM_ARM)
#define ELF_USES_RELOC

#elif defined(HOST_M68K)

#define ELF_CLASS       ELFCLASS32
#define ELF_ARCH        EM_68K
#define elf_check_arch(x) ((x) == EM_68K)
#define ELF_USES_RELOCA

#else
#error unsupported CPU - please update the code
#endif

#include "elf.h"

#if ELF_CLASS == ELFCLASS32
typedef int32_t host_long;
typedef uint32_t host_ulong;
#define swabls(x) swab32s(x)
#define swablss(x) swab32ss(x)
#else
typedef int64_t host_long;
typedef uint64_t host_ulong;
#define swabls(x) swab64s(x)
#define swablss(x) swab64ss(x)
#endif

#ifdef ELF_USES_RELOCA
#define SHT_RELOC SHT_RELA
#else
#define SHT_RELOC SHT_REL
#endif

#define EXE_RELOC ELF_RELOC
#define EXE_SYM ElfW(Sym)

#endif /* CONFIG_FORMAT_ELF */

#ifdef CONFIG_FORMAT_COFF

#include "a.out.h"

typedef int32_t host_long;
typedef uint32_t host_ulong;

#define FILENAMELEN 256

typedef struct coff_sym {
    struct external_syment *st_syment;
    char st_name[FILENAMELEN];
    uint32_t st_value;
    int  st_size;
    uint8_t st_type;
    uint8_t st_shndx;
} coff_Sym;

typedef struct coff_rel {
    struct external_reloc *r_reloc;
    int  r_offset;
    uint8_t r_type;
} coff_Rel;

#define EXE_RELOC struct coff_rel
#define EXE_SYM struct coff_sym

#endif /* CONFIG_FORMAT_COFF */

#ifdef CONFIG_FORMAT_MACH

#include <mach-o/loader.h>
#include <mach-o/nlist.h>
#include <mach-o/reloc.h>
#if !defined(HOST_I386)
#include <mach-o/ppc/reloc.h>
#endif 

# define check_mach_header(x) (x.magic == MH_MAGIC)
typedef int32_t host_long;
typedef uint32_t host_ulong;

struct nlist_extended
{
   union {
   char *n_name; 
   long  n_strx; 
   } n_un;
   unsigned char n_type; 
   unsigned char n_sect; 
   short st_desc;
   unsigned long st_value;
   unsigned long st_size;
};

#define EXE_RELOC struct relocation_info
#define EXE_SYM struct nlist_extended
#if defined(HOST_I386)
# define r_offset r_address
#endif 

#endif /* CONFIG_FORMAT_MACH */

#ifdef CONFIG_FORMAT_AOUT

#include "a_out.h"

typedef int32_t host_long;
typedef uint32_t host_ulong;

struct nlist_extended
{
    union {
      char *n_name;
      struct nlist *n_next;
      long n_strx;
    } n_un;
    unsigned char n_type;
    char n_other;
    short n_desc;
    unsigned long st_value; /* n_value -> st_value */
    unsigned long st_size;  /* added */
};

#define EXE_RELOC struct relocation_info
#define EXE_SYM struct nlist_extended
#define r_offset r_address

#endif /* CONFIG_FORMAT_AOUT */

#include "bswap.h"

enum {
    OUT_GEN_OP,
    OUT_CODE,
    OUT_INDEX_OP
};

/* all dynamically generated functions begin with this code */
#define OP_PREFIX "op_"

int do_swap;

void __attribute__((noreturn)) __attribute__((format (printf, 1, 2))) error(const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    fprintf(stderr, "dyngen: ");
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
    va_end(ap);
    exit(1);
}

void *load_data(int fd, long offset, unsigned int size)
{
    char *data;

    data = malloc(size);
    if (!data)
        return NULL;
    lseek(fd, offset, SEEK_SET);
    if (read(fd, data, size) != size) {
        free(data);
        return NULL;
    }
    return data;
}

int strstart(const char *str, const char *val, const char **ptr)
{
    const char *p, *q;
    p = str;
    q = val;
    while (*q != '\0') {
        if (*p != *q)
            return 0;
        p++;
        q++;
    }
    if (ptr)
        *ptr = p;
    return 1;
}

void pstrcpy(char *buf, int buf_size, const char *str)
{
    int c;
    char *q = buf;

    if (buf_size <= 0)
        return;

    for(;;) {
        c = *str++;
        if (c == 0 || q >= buf + buf_size - 1)
            break;
        *q++ = c;
    }
    *q = '\0';
}

void swab16s(uint16_t *p)
{
    *p = bswap16(*p);
}

void swab32s(uint32_t *p)
{
    *p = bswap32(*p);
}

void swab32ss(int32_t *p)
{
    *p = bswap32(*p);
}

void swab64s(uint64_t *p)
{
    *p = bswap64(*p);
}

void swab64ss(int64_t *p)
{
    *p = bswap64(*p);
}

uint16_t get16(uint16_t *p)
{
    uint16_t val;
    val = *p;
    if (do_swap)
        val = bswap16(val);
    return val;
}

uint32_t get32(uint32_t *p)
{
    uint32_t val;
    val = *p;
    if (do_swap)
        val = bswap32(val);
    return val;
}

void put16(uint16_t *p, uint16_t val)
{
    if (do_swap)
        val = bswap16(val);
    *p = val;
}

void put32(uint32_t *p, uint32_t val)
{
    if (do_swap)
        val = bswap32(val);
    *p = val;
}

/* executable information */
EXE_SYM *symtab;
int nb_syms;
int text_shndx;
uint8_t *text;
EXE_RELOC *relocs;
int nb_relocs;

#ifdef CONFIG_FORMAT_ELF

/* ELF file info */
struct elf_shdr *shdr;
uint8_t **sdata;
struct elfhdr ehdr;
char *strtab;

int elf_must_swap(struct elfhdr *h)
{
  union {
      uint32_t i;
      uint8_t b[4];
  } swaptest;

  swaptest.i = 1;
  return (h->e_ident[EI_DATA] == ELFDATA2MSB) != 
      (swaptest.b[0] == 0);
}
  
void elf_swap_ehdr(struct elfhdr *h)
{
    swab16s(&h->e_type);                        /* Object file type */
    swab16s(&h->        e_machine);             /* Architecture */
    swab32s(&h->        e_version);             /* Object file version */
    swabls(&h-> e_entry);               /* Entry point virtual address */
    swabls(&h-> e_phoff);               /* Program header table file offset */
    swabls(&h-> e_shoff);               /* Section header table file offset */
    swab32s(&h->        e_flags);               /* Processor-specific flags */
    swab16s(&h->        e_ehsize);              /* ELF header size in bytes */
    swab16s(&h->        e_phentsize);           /* Program header table entry size */
    swab16s(&h->        e_phnum);               /* Program header table entry count */
    swab16s(&h->        e_shentsize);           /* Section header table entry size */
    swab16s(&h->        e_shnum);               /* Section header table entry count */
    swab16s(&h->        e_shstrndx);            /* Section header string table index */
}

void elf_swap_shdr(struct elf_shdr *h)
{
  swab32s(&h->  sh_name);               /* Section name (string tbl index) */
  swab32s(&h->  sh_type);               /* Section type */
  swabls(&h->   sh_flags);              /* Section flags */
  swabls(&h->   sh_addr);               /* Section virtual addr at execution */
  swabls(&h->   sh_offset);             /* Section file offset */
  swabls(&h->   sh_size);               /* Section size in bytes */
  swab32s(&h->  sh_link);               /* Link to another section */
  swab32s(&h->  sh_info);               /* Additional section information */
  swabls(&h->   sh_addralign);          /* Section alignment */
  swabls(&h->   sh_entsize);            /* Entry size if section holds table */
}

void elf_swap_phdr(struct elf_phdr *h)
{
    swab32s(&h->p_type);                        /* Segment type */
    swabls(&h->p_offset);               /* Segment file offset */
    swabls(&h->p_vaddr);                /* Segment virtual address */
    swabls(&h->p_paddr);                /* Segment physical address */
    swabls(&h->p_filesz);               /* Segment size in file */
    swabls(&h->p_memsz);                /* Segment size in memory */
    swab32s(&h->p_flags);               /* Segment flags */
    swabls(&h->p_align);                /* Segment alignment */
}

void elf_swap_rel(ELF_RELOC *rel)
{
    swabls(&rel->r_offset);
    swabls(&rel->r_info);
#ifdef ELF_USES_RELOCA
    swablss(&rel->r_addend);
#endif
}

struct elf_shdr *find_elf_section(struct elf_shdr *shdr, int shnum, const char *shstr, 
                                  const char *name)
{
    int i;
    const char *shname;
    struct elf_shdr *sec;

    for(i = 0; i < shnum; i++) {
        sec = &shdr[i];
        if (!sec->sh_name)
            continue;
        shname = shstr + sec->sh_name;
        if (!strcmp(shname, name))
            return sec;
    }
    return NULL;
}

int find_reloc(int sh_index)
{
    struct elf_shdr *sec;
    int i;

    for(i = 0; i < ehdr.e_shnum; i++) {
        sec = &shdr[i];
        if (sec->sh_type == SHT_RELOC && sec->sh_info == sh_index) 
            return i;
    }
    return 0;
}

static host_ulong get_rel_offset(EXE_RELOC *rel)
{
    return rel->r_offset;
}

static char *get_rel_sym_name(EXE_RELOC *rel)
{
    return strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
}

static char *get_sym_name(EXE_SYM *sym)
{
    return strtab + sym->st_name;
}

/* load an elf object file */
int load_object(const char *filename)
{
    int fd;
    struct elf_shdr *sec, *symtab_sec, *strtab_sec, *text_sec;
    int i, j;
    ElfW(Sym) *sym;
    char *shstr;
    ELF_RELOC *rel;
    
    fd = open(filename, O_RDONLY
#ifdef O_BINARY
              | O_BINARY
#endif 
              );
    if (fd < 0) 
        error("can't open file '%s'", filename);
    
    /* Read ELF header.  */
    if (read(fd, &ehdr, sizeof (ehdr)) != sizeof (ehdr))
        error("unable to read file header");

    /* Check ELF identification.  */
    if (ehdr.e_ident[EI_MAG0] != ELFMAG0
     || ehdr.e_ident[EI_MAG1] != ELFMAG1
     || ehdr.e_ident[EI_MAG2] != ELFMAG2
     || ehdr.e_ident[EI_MAG3] != ELFMAG3
     || ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
        error("bad ELF header");
    }

    do_swap = elf_must_swap(&ehdr);
    if (do_swap)
        elf_swap_ehdr(&ehdr);
    if (ehdr.e_ident[EI_CLASS] != ELF_CLASS)
        error("Unsupported ELF class (%#x)", ehdr.e_ident[EI_CLASS]);
    if (ehdr.e_type != ET_REL)
        error("ELF object file expected");
    if (ehdr.e_version != EV_CURRENT)
        error("Invalid ELF version");
    if (!elf_check_arch(ehdr.e_machine))
        error("Unsupported CPU (e_machine=%d)", ehdr.e_machine);

    /* read section headers */
    shdr = load_data(fd, ehdr.e_shoff, ehdr.e_shnum * sizeof(struct elf_shdr));
    if (do_swap) {
        for(i = 0; i < ehdr.e_shnum; i++) {
            elf_swap_shdr(&shdr[i]);
        }
    }

    /* read all section data */
    sdata = malloc(sizeof(void *) * ehdr.e_shnum);
    memset(sdata, 0, sizeof(void *) * ehdr.e_shnum);
    
    for(i = 0;i < ehdr.e_shnum; i++) {
        sec = &shdr[i];
        if (sec->sh_type != SHT_NOBITS)
            sdata[i] = load_data(fd, sec->sh_offset, sec->sh_size);
    }

    sec = &shdr[ehdr.e_shstrndx];
    shstr = (char *)sdata[ehdr.e_shstrndx];

    /* swap relocations */
    for(i = 0; i < ehdr.e_shnum; i++) {
        sec = &shdr[i];
        if (sec->sh_type == SHT_RELOC) {
            nb_relocs = sec->sh_size / sec->sh_entsize;
            if (do_swap) {
                for(j = 0, rel = (ELF_RELOC *)sdata[i]; j < nb_relocs; j++, rel++)
                    elf_swap_rel(rel);
            }
        }
    }
    /* text section */

    text_sec = find_elf_section(shdr, ehdr.e_shnum, shstr, ".text");
    if (!text_sec)
        error("could not find .text section");
    text_shndx = text_sec - shdr;
    text = sdata[text_shndx];

    /* find text relocations, if any */
    relocs = NULL;
    nb_relocs = 0;
    i = find_reloc(text_shndx);
    if (i != 0) {
        relocs = (ELF_RELOC *)sdata[i];
        nb_relocs = shdr[i].sh_size / shdr[i].sh_entsize;
    }

    symtab_sec = find_elf_section(shdr, ehdr.e_shnum, shstr, ".symtab");
    if (!symtab_sec)
        error("could not find .symtab section");
    strtab_sec = &shdr[symtab_sec->sh_link];

    symtab = (ElfW(Sym) *)sdata[symtab_sec - shdr];
    strtab = (char *)sdata[symtab_sec->sh_link];
    
    nb_syms = symtab_sec->sh_size / sizeof(ElfW(Sym));
    if (do_swap) {
        for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
            swab32s(&sym->st_name);
            swabls(&sym->st_value);
            swabls(&sym->st_size);
            swab16s(&sym->st_shndx);
        }
    }
    close(fd);
    return 0;
}

#endif /* CONFIG_FORMAT_ELF */

#ifdef CONFIG_FORMAT_COFF

/* COFF file info */
struct external_scnhdr *shdr;
uint8_t **sdata;
struct external_filehdr fhdr;
struct external_syment *coff_symtab;
char *strtab;
int coff_text_shndx, coff_data_shndx;

int data_shndx;

#define STRTAB_SIZE 4

#define DIR32   0x06
#define DISP32  0x14

#define T_FUNCTION  0x20
#define C_EXTERNAL  2

void sym_ent_name(struct external_syment *ext_sym, EXE_SYM *sym)
{
    char *q;
    int c, i, len;
    
    if (ext_sym->e.e.e_zeroes != 0) {
        q = sym->st_name;
        for(i = 0; i < 8; i++) {
            c = ext_sym->e.e_name[i];
            if (c == '\0')
                break;
            *q++ = c;
        }
        *q = '\0';
    } else {
        pstrcpy(sym->st_name, sizeof(sym->st_name), strtab + ext_sym->e.e.e_offset);
    }

    /* now convert the name to a C name (suppress the leading '_') */
    if (sym->st_name[0] == '_') {
        len = strlen(sym->st_name);
        memmove(sym->st_name, sym->st_name + 1, len - 1);
        sym->st_name[len - 1] = '\0';
    }
}

char *name_for_dotdata(struct coff_rel *rel)
{
        int i;
        struct coff_sym *sym;
        uint32_t text_data;

        text_data = *(uint32_t *)(text + rel->r_offset);

        for (i = 0, sym = symtab; i < nb_syms; i++, sym++) {
                if (sym->st_syment->e_scnum == data_shndx &&
                    text_data >= sym->st_value &&
                    text_data < sym->st_value + sym->st_size) {
                    
                    return sym->st_name;

                }
        }
        return NULL;
}

static char *get_sym_name(EXE_SYM *sym)
{
    return sym->st_name;
}

static char *get_rel_sym_name(EXE_RELOC *rel)
{
    char *name;
    name = get_sym_name(symtab + *(uint32_t *)(rel->r_reloc->r_symndx));
    if (!strcmp(name, ".data"))
        name = name_for_dotdata(rel);
    if (name[0] == '.')
        return NULL;
    return name;
}

static host_ulong get_rel_offset(EXE_RELOC *rel)
{
    return rel->r_offset;
}

struct external_scnhdr *find_coff_section(struct external_scnhdr *shdr, int shnum, const char *name)
{
    int i;
    const char *shname;
    struct external_scnhdr *sec;

    for(i = 0; i < shnum; i++) {
        sec = &shdr[i];
        if (!sec->s_name)
            continue;
        shname = sec->s_name;
        if (!strcmp(shname, name))
            return sec;
    }
    return NULL;
}

/* load a coff object file */
int load_object(const char *filename)
{
    int fd;
    struct external_scnhdr *sec, *text_sec, *data_sec;
    int i;
    struct external_syment *ext_sym;
    struct external_reloc *coff_relocs;
    struct external_reloc *ext_rel;
    uint32_t *n_strtab;
    EXE_SYM *sym;
    EXE_RELOC *rel;
        
    fd = open(filename, O_RDONLY 
#ifdef O_BINARY
              | O_BINARY
#endif
              );
    if (fd < 0) 
        error("can't open file '%s'", filename);
    
    /* Read COFF header.  */
    if (read(fd, &fhdr, sizeof (fhdr)) != sizeof (fhdr))
        error("unable to read file header");

    /* Check COFF identification.  */
    if (fhdr.f_magic != I386MAGIC) {
        error("bad COFF header");
    }
    do_swap = 0;

    /* read section headers */
    shdr = load_data(fd, sizeof(struct external_filehdr) + fhdr.f_opthdr, fhdr.f_nscns * sizeof(struct external_scnhdr));
        
    /* read all section data */
    sdata = malloc(sizeof(void *) * fhdr.f_nscns);
    memset(sdata, 0, sizeof(void *) * fhdr.f_nscns);
    
    const char *p;
    for(i = 0;i < fhdr.f_nscns; i++) {
        sec = &shdr[i];
        if (!strstart(sec->s_name,  ".bss", &p))
            sdata[i] = load_data(fd, sec->s_scnptr, sec->s_size);
    }


    /* text section */
    text_sec = find_coff_section(shdr, fhdr.f_nscns, ".text");
    if (!text_sec)
        error("could not find .text section");
    coff_text_shndx = text_sec - shdr;
    text = sdata[coff_text_shndx];

    /* data section */
    data_sec = find_coff_section(shdr, fhdr.f_nscns, ".data");
    if (!data_sec)
        error("could not find .data section");
    coff_data_shndx = data_sec - shdr;
    
    coff_symtab = load_data(fd, fhdr.f_symptr, fhdr.f_nsyms*SYMESZ);
    for (i = 0, ext_sym = coff_symtab; i < nb_syms; i++, ext_sym++) {
        for(i=0;i<8;i++)
            printf(" %02x", ((uint8_t *)ext_sym->e.e_name)[i]);
        printf("\n");
    }


    n_strtab = load_data(fd, (fhdr.f_symptr + fhdr.f_nsyms*SYMESZ), STRTAB_SIZE);
    strtab = load_data(fd, (fhdr.f_symptr + fhdr.f_nsyms*SYMESZ), *n_strtab); 
    
    nb_syms = fhdr.f_nsyms;

    for (i = 0, ext_sym = coff_symtab; i < nb_syms; i++, ext_sym++) {
      if (strstart(ext_sym->e.e_name, ".text", NULL))
                  text_shndx = ext_sym->e_scnum;
          if (strstart(ext_sym->e.e_name, ".data", NULL))
                  data_shndx = ext_sym->e_scnum;
    }

        /* set coff symbol */
        symtab = malloc(sizeof(struct coff_sym) * nb_syms);

        int aux_size, j;
        for (i = 0, ext_sym = coff_symtab, sym = symtab; i < nb_syms; i++, ext_sym++, sym++) {
                memset(sym, 0, sizeof(*sym));
                sym->st_syment = ext_sym;
                sym_ent_name(ext_sym, sym);
                sym->st_value = ext_sym->e_value;

                aux_size = *(int8_t *)ext_sym->e_numaux;
                if (ext_sym->e_scnum == text_shndx && ext_sym->e_type == T_FUNCTION) {
                        for (j = aux_size + 1; j < nb_syms - i; j++) {
                                if ((ext_sym + j)->e_scnum == text_shndx &&
                                        (ext_sym + j)->e_type == T_FUNCTION ){
                                        sym->st_size = (ext_sym + j)->e_value - ext_sym->e_value;
                                        break;
                                } else if (j == nb_syms - i - 1) {
                                        sec = &shdr[coff_text_shndx];
                                        sym->st_size = sec->s_size - ext_sym->e_value;
                                        break;
                                }
                        }
                } else if (ext_sym->e_scnum == data_shndx && *(uint8_t *)ext_sym->e_sclass == C_EXTERNAL) {
                        for (j = aux_size + 1; j < nb_syms - i; j++) {
                                if ((ext_sym + j)->e_scnum == data_shndx) {
                                        sym->st_size = (ext_sym + j)->e_value - ext_sym->e_value;
                                        break;
                                } else if (j == nb_syms - i - 1) {
                                        sec = &shdr[coff_data_shndx];
                                        sym->st_size = sec->s_size - ext_sym->e_value;
                                        break;
                                }
                        }
                } else {
                        sym->st_size = 0;
                }
                
                sym->st_type = ext_sym->e_type;
                sym->st_shndx = ext_sym->e_scnum;
        }

                
    /* find text relocations, if any */
    sec = &shdr[coff_text_shndx];
    coff_relocs = load_data(fd, sec->s_relptr, sec->s_nreloc*RELSZ);
    nb_relocs = sec->s_nreloc;

    /* set coff relocation */
    relocs = malloc(sizeof(struct coff_rel) * nb_relocs);
    for (i = 0, ext_rel = coff_relocs, rel = relocs; i < nb_relocs; 
         i++, ext_rel++, rel++) {
        memset(rel, 0, sizeof(*rel));
        rel->r_reloc = ext_rel;
        rel->r_offset = *(uint32_t *)ext_rel->r_vaddr;
        rel->r_type = *(uint16_t *)ext_rel->r_type;
    }
    return 0;
}

#endif /* CONFIG_FORMAT_COFF */

#ifdef CONFIG_FORMAT_MACH

/* File Header */
struct mach_header      mach_hdr;

/* commands */
struct segment_command  *segment = 0;
struct dysymtab_command *dysymtabcmd = 0;
struct symtab_command   *symtabcmd = 0;

/* section */
struct section  *section_hdr;
struct section *text_sec_hdr;
uint8_t         **sdata;

/* relocs */
struct relocation_info *relocs;
        
/* symbols */
EXE_SYM                 *symtab;
struct nlist    *symtab_std;
char                    *strtab;

/* indirect symbols */
uint32_t        *tocdylib;

/* Utility functions */

static inline char *find_str_by_index(int index)
{
    return strtab+index;
}

/* Used by dyngen common code */
static char *get_sym_name(EXE_SYM *sym)
{
        char *name = find_str_by_index(sym->n_un.n_strx);
        
        if ( sym->n_type & N_STAB ) /* Debug symbols are ignored */
                return "debug";
                        
        if(!name)
                return name;
        if(name[0]=='_')
                return name + 1;
        else
                return name;
}

/* find a section index given its segname, sectname */
static int find_mach_sec_index(struct section *section_hdr, int shnum, const char *segname, 
                                  const char *sectname)
{
    int i;
    struct section *sec = section_hdr;

    for(i = 0; i < shnum; i++, sec++) {
        if (!sec->segname || !sec->sectname)
            continue;
        if (!strcmp(sec->sectname, sectname) && !strcmp(sec->segname, segname))
            return i;
    }
    return -1;
}

/* find a section header given its segname, sectname */
struct section *find_mach_sec_hdr(struct section *section_hdr, int shnum, const char *segname, 
                                  const char *sectname)
{
    int index = find_mach_sec_index(section_hdr, shnum, segname, sectname);
        if(index == -1)
                return NULL;
        return section_hdr+index;
}