source: vbox/trunk/src/recompiler/dyngen.c@ 13021

/*
 *  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;
}


#if defined(HOST_PPC)
static inline void fetch_next_pair_value(struct relocation_info * rel, unsigned int *value)
{
    struct scattered_relocation_info * scarel;
        
    if(R_SCATTERED & rel->r_address) {
        scarel = (struct scattered_relocation_info*)rel;
        if(scarel->r_type != PPC_RELOC_PAIR)
            error("fetch_next_pair_value: looking for a pair which was not found (1)");
        *value = scarel->r_value;
    } else {
                if(rel->r_type != PPC_RELOC_PAIR)
                        error("fetch_next_pair_value: looking for a pair which was not found (2)");
                *value = rel->r_address;
        }
}
#endif

/* find a sym name given its value, in a section number */
static const char * find_sym_with_value_and_sec_number( int value, int sectnum, int * offset )
{
        int i, ret = -1;
        
        for( i = 0 ; i < nb_syms; i++ )
        {
            if( !(symtab[i].n_type & N_STAB) && (symtab[i].n_type & N_SECT) &&
                         (symtab[i].n_sect ==  sectnum) && (symtab[i].st_value <= value) )
                {
                        if( (ret<0) || (symtab[i].st_value >= symtab[ret].st_value) )
                                ret = i;
                }
        }
        if( ret < 0 ) {
                *offset = 0;
                return 0;
        } else {
                *offset = value - symtab[ret].st_value;
                return get_sym_name(&symtab[ret]);
        }
}

/* 
 *  Find symbol name given a (virtual) address, and a section which is of type 
 *  S_NON_LAZY_SYMBOL_POINTERS or S_LAZY_SYMBOL_POINTERS or S_SYMBOL_STUBS
 */
static const char * find_reloc_name_in_sec_ptr(int address, struct section * sec_hdr)
{
    unsigned int tocindex, symindex, size;
    const char *name = 0;
    
    /* Sanity check */
    if(!( address >= sec_hdr->addr && address < (sec_hdr->addr + sec_hdr->size) ) )
        return (char*)0;
                
        if( sec_hdr->flags & S_SYMBOL_STUBS ){
                size = sec_hdr->reserved2;
                if(size == 0)
                    error("size = 0");
                
        }
        else if( sec_hdr->flags & S_LAZY_SYMBOL_POINTERS ||
                    sec_hdr->flags & S_NON_LAZY_SYMBOL_POINTERS)
                size = sizeof(unsigned long);
        else
                return 0;
                
    /* Compute our index in toc */
        tocindex = (address - sec_hdr->addr)/size;
        symindex = tocdylib[sec_hdr->reserved1 + tocindex];
        
        name = get_sym_name(&symtab[symindex]);

    return name;
}

static const char * find_reloc_name_given_its_address(int address)
{
    unsigned int i;
    for(i = 0; i < segment->nsects ; i++)
    {
        const char * name = find_reloc_name_in_sec_ptr(address, &section_hdr[i]);
        if((long)name != -1)
            return name;
    }
    return 0;
}

static const char * get_reloc_name(EXE_RELOC * rel, int * sslide)
{
        char * name = 0;
        struct scattered_relocation_info * sca_rel = (struct scattered_relocation_info*)rel;
        int sectnum = rel->r_symbolnum;
        int sectoffset;
        int other_half=0;
        
        /* init the slide value */
        *sslide = 0;
        
        if(R_SCATTERED & rel->r_address)
                return (char *)find_reloc_name_given_its_address(sca_rel->r_value);

        if(rel->r_extern)
        {
                /* ignore debug sym */
                if ( symtab[rel->r_symbolnum].n_type & N_STAB ) 
                        return 0;
                return get_sym_name(&symtab[rel->r_symbolnum]);
        }

#if defined(HOST_I386)
        /* ignore internal pc relative fixups where both ends are in the text section. */
        if (rel->r_pcrel && !rel->r_extern && rel->r_symbolnum == 1 /* ASSUMES text */)
                return NULL;
#endif 

        /* Intruction contains an offset to the symbols pointed to, in the rel->r_symbolnum section */
        sectoffset = *(uint32_t *)(text + rel->r_address) & 0xffff;
                        
        if(sectnum==0xffffff)
                return 0;

        /* Sanity Check */
        if(sectnum > segment->nsects)
                error("sectnum > segment->nsects");

#if defined(HOST_PPC)
        switch(rel->r_type)
        {
                case PPC_RELOC_LO16: fetch_next_pair_value(rel+1, &other_half); sectoffset |= (other_half << 16);
                        break;
                case PPC_RELOC_HI16: fetch_next_pair_value(rel+1, &other_half); sectoffset = (sectoffset << 16) | (uint16_t)(other_half & 0xffff);
                        break;
                case PPC_RELOC_HA16: fetch_next_pair_value(rel+1, &other_half); sectoffset = (sectoffset << 16) + (int16_t)(other_half & 0xffff);
                        break;
                case PPC_RELOC_BR24:
                        sectoffset = ( *(uint32_t *)(text + rel->r_address) & 0x03fffffc );
                        if (sectoffset & 0x02000000) sectoffset |= 0xfc000000;
                        break;
                default:
                        error("switch(rel->type) not found");
        }
#elif defined(HOST_I386)
        /* The intruction contains the addend. */
        sectoffset = *(uint32_t *)(text + rel->r_address);
#else
#error unsupported mach-o host
#endif 

        if(rel->r_pcrel)
                sectoffset += rel->r_address;
                        
#if defined(HOST_PPC)
        if (rel->r_type == PPC_RELOC_BR24)
                name = (char *)find_reloc_name_in_sec_ptr((int)sectoffset, &section_hdr[sectnum-1]);
#endif

        /* search it in the full symbol list, if not found */
        if(!name)
                name = (char *)find_sym_with_value_and_sec_number(sectoffset, sectnum, sslide);
        
        return name;
}

#if defined(HOST_I386)
static const char *get_rel_sym_name_and_addend(EXE_RELOC *rel, int *addend)
{
        const char *name = NULL;

    if (R_SCATTERED & rel->r_address) {
                unsigned int i;
                struct scattered_relocation_info * sca_rel = (struct scattered_relocation_info*)rel;
                if (sca_rel->r_length != 2 || rel->r_pcrel) {
                        error("Fully implement R_SCATTERED! r_address=%#x r_type=%#x r_length=%d r_pcrel=%d r_value=%#x\n", 
                                  (int)sca_rel->r_address, sca_rel->r_type, sca_rel->r_length, sca_rel->r_pcrel, sca_rel->r_value);
                }

                /* this seems to be the way to calc the addend. */
                *addend = *(int32_t *)(text + sca_rel->r_address) - sca_rel->r_value;

                /* todo: do we need to ignore internal relocations? */
#if 0
                if (sca_rel->r_pcrel ...)
                        return NULL;
#endif

                /* find_reloc_name_given_its_address doesn't do the right thing here, so 
                   we locate the section and use find_sym_with_value_and_sec_number  */
                for (i = 0; i < segment->nsects ; i++) {
                        if ((uintptr_t)sca_rel->r_value - section_hdr[i].addr < section_hdr[i].size) {
                                int off = 0;
                                name = find_sym_with_value_and_sec_number(sca_rel->r_value, i + 1, &off);
                                if (name) {
                                        *addend += off;
                                         break;
                                }
                        }
                }
                if (!name)
                        error("Fully implement R_SCATTERED! r_address=%#x r_type=%#x r_length=%d r_pcrel=%d r_value=%#x\n", 
                                  (int)sca_rel->r_address, sca_rel->r_type, sca_rel->r_length, sca_rel->r_pcrel, sca_rel->r_value);
        }
        else 
        {
                /* ignore debug syms (paranoia). */
                if (symtab[rel->r_symbolnum].n_type & N_STAB)
                        return NULL;

                /* ignore internal pc relative fixups where both ends are in the text section. */
                if (rel->r_pcrel && !rel->r_extern && rel->r_symbolnum == 1 /* ASSUMES text */)
                        return NULL;

                /* get the addend, it is in the instruction stream. */
                *addend = *(int32_t *)(text + rel->r_address);
                if (rel->r_pcrel)
                        *addend += rel->r_address;

                /* external fixups are easy. */
                if (rel->r_extern)
                {
                        if (rel->r_symbolnum >= nb_syms) 
                                error("rel->r_symbolnum (%d) >= nb_syms (%d)", rel->r_symbolnum, nb_syms);
                        name = get_sym_name(&symtab[rel->r_symbolnum]);
                }
                else
                {
                        /* sanity checks. */
                        if (rel->r_symbolnum == 0xffffff)
                                return NULL;
                        if (rel->r_symbolnum > segment->nsects)
                                error("sectnum (%d) > segment->nsects (%d)", rel->r_symbolnum, segment->nsects);
                        if (rel->r_pcrel) 
                                error("internal pcrel fixups not implemented");

                        /* search for the symbol. */
                        name = find_sym_with_value_and_sec_number(*addend, rel->r_symbolnum, addend);
                }
        }
    return name;
}
#endif /* HOST_I386 */

/* Used by dyngen common code */
static const char * get_rel_sym_name(EXE_RELOC * rel)
{
        int sslide;
#if defined(HOST_I386)
        return get_rel_sym_name_and_addend(rel, &sslide);
#else
        return get_reloc_name( rel, &sslide);
#endif
}

/* Used by dyngen common code */
static host_ulong get_rel_offset(EXE_RELOC *rel)
{
        struct scattered_relocation_info * sca_rel = (struct scattered_relocation_info*)rel;
    if(R_SCATTERED & rel->r_address)
                return sca_rel->r_address;
        else
                return rel->r_address;
}

/* load a mach-o object file */
int load_object(const char *filename)
{
        int fd;
        unsigned int offset_to_segment = 0;
    unsigned int offset_to_dysymtab = 0;
    unsigned int offset_to_symtab = 0;
    struct load_command lc;
    unsigned int i, j;
        EXE_SYM *sym;
        struct nlist *syment;
    
        fd = open(filename, O_RDONLY
#ifdef O_BINARY
                  | O_BINARY
#endif
                  );
    if (fd < 0) 
        error("can't open file '%s'", filename);
                
    /* Read Mach header.  */
    if (read(fd, &mach_hdr, sizeof (mach_hdr)) != sizeof (mach_hdr))
        error("unable to read file header");

    /* Check Mach identification.  */
    if (!check_mach_header(mach_hdr)) {
        error("bad Mach header");
    }

#if defined(HOST_PPC)
    if (mach_hdr.cputype != CPU_TYPE_POWERPC)
#elif defined(HOST_I386)
    if (mach_hdr.cputype != CPU_TYPE_X86)
#else
#error unsupported host
#endif 
        error("Unsupported CPU");
        
    if (mach_hdr.filetype != MH_OBJECT)
        error("Unsupported Mach Object");
    
    /* read segment headers */
    for(i=0, j=sizeof(mach_hdr); i<mach_hdr.ncmds ; i++)
    {
        if(read(fd, &lc, sizeof(struct load_command)) != sizeof(struct load_command))
            error("unable to read load_command");
        if(lc.cmd == LC_SEGMENT)
        {
            offset_to_segment = j;
            lseek(fd, offset_to_segment, SEEK_SET);
            segment = malloc(sizeof(struct segment_command));
            if(read(fd, segment, sizeof(struct segment_command)) != sizeof(struct segment_command))
                error("unable to read LC_SEGMENT");
        }
        if(lc.cmd == LC_DYSYMTAB)
        {
            offset_to_dysymtab = j;
            lseek(fd, offset_to_dysymtab, SEEK_SET);
            dysymtabcmd = malloc(sizeof(struct dysymtab_command));
            if(read(fd, dysymtabcmd, sizeof(struct dysymtab_command)) != sizeof(struct dysymtab_command))
                error("unable to read LC_DYSYMTAB");
        }
        if(lc.cmd == LC_SYMTAB)
        {
            offset_to_symtab = j;
            lseek(fd, offset_to_symtab, SEEK_SET);
            symtabcmd = malloc(sizeof(struct symtab_command));
            if(read(fd, symtabcmd, sizeof(struct symtab_command)) != sizeof(struct symtab_command))
                error("unable to read LC_SYMTAB");
        }
        j+=lc.cmdsize;

        lseek(fd, j, SEEK_SET);
    }

    if(!segment)
        error("unable to find LC_SEGMENT");

    /* read section headers */
    section_hdr = load_data(fd, offset_to_segment + sizeof(struct segment_command), segment->nsects * sizeof(struct section));

    /* read all section data */
    sdata = (uint8_t **)malloc(sizeof(void *) * segment->nsects);
    memset(sdata, 0, sizeof(void *) * segment->nsects);
    
        /* Load the data in section data */
        for(i = 0; i < segment->nsects; i++) {
        sdata[i] = load_data(fd, section_hdr[i].offset, section_hdr[i].size);
    }
        
    /* text section */
        text_sec_hdr = find_mach_sec_hdr(section_hdr, segment->nsects, SEG_TEXT, SECT_TEXT);
        i = find_mach_sec_index(section_hdr, segment->nsects, SEG_TEXT, SECT_TEXT);
        if (i == -1 || !text_sec_hdr)
        error("could not find __TEXT,__text section");
    text = sdata[i];
        
    /* Make sure dysym was loaded */
    if(!(int)dysymtabcmd)
        error("could not find __DYSYMTAB segment");
    
    /* read the table of content of the indirect sym */
    tocdylib = load_data( fd, dysymtabcmd->indirectsymoff, dysymtabcmd->nindirectsyms * sizeof(uint32_t) );
    
    /* Make sure symtab was loaded  */
    if(!(int)symtabcmd)
        error("could not find __SYMTAB segment");
    nb_syms = symtabcmd->nsyms;

    symtab_std = load_data(fd, symtabcmd->symoff, symtabcmd->nsyms * sizeof(struct nlist));
    strtab = load_data(fd, symtabcmd->stroff, symtabcmd->strsize);
        
        symtab = malloc(sizeof(EXE_SYM) * nb_syms);
        
        /* Now transform the symtab, to an extended version, with the sym size, and the C name */
        for(i = 0, sym = symtab, syment = symtab_std; i < nb_syms; i++, sym++, syment++) {
        struct nlist *sym_cur, *sym_next = 0;
        unsigned int j;
                memset(sym, 0, sizeof(*sym));
                
                if ( syment->n_type & N_STAB ) /* Debug symbols are skipped */
            continue;
                        
                memcpy(sym, syment, sizeof(*syment));

#if defined(VBOX)
        /* don't bother calcing size of internal symbol local symbols. */
        if (strstart(find_str_by_index(sym->n_un.n_strx), ".L", NULL)) {
            sym->st_size = 0;
            continue;
        }
#endif 
                        
                /* Find the following symbol in order to get the current symbol size */
        for (j = 0, sym_cur = symtab_std; j < nb_syms; j++, sym_cur++) {
            if (    sym_cur->n_sect != /*syment->n_sect*/ 1
                ||  (sym_cur->n_type & N_STAB)
                ||  sym_cur->n_value <= syment->n_value)
                continue;
            if (     sym_next
                &&   sym_next->n_value <= sym_cur->n_value)
                continue;
#if defined(HOST_I386)
            /* Ignore local labels (.Lxxx). */
            if (strstart(find_str_by_index(sym_cur->n_un.n_strx), ".L", NULL))
                continue;
#endif 
            /* a good one */
            sym_next = sym_cur;
        }
                if(sym_next)
            sym->st_size = sym_next->n_value - sym->st_value;
                else
            sym->st_size = text_sec_hdr->size - sym->st_value;
        }
        
    /* Find Reloc */
    relocs = load_data(fd, text_sec_hdr->reloff, text_sec_hdr->nreloc * sizeof(struct relocation_info));
    nb_relocs = text_sec_hdr->nreloc;

        close(fd);
        return 0;
}

#endif /* CONFIG_FORMAT_MACH */

#ifdef CONFIG_FORMAT_AOUT

struct exec *aout_hdr;
struct nlist *symtab_std;
char *strtab;


/* 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 && name[0] == '_')
        return name + 1;
    return name;
}

static int type_to_sec_number(unsigned type)
{
    switch (type)
    {
        case 0:       case 0     |N_EXT:    case N_WEAKU:   return N_UNDF;
        case N_ABS:   case N_ABS |N_EXT:    case N_WEAKA:   return N_ABS;
        case N_TEXT:  case N_TEXT|N_EXT:    case N_WEAKT:   return N_TEXT;
        case N_DATA:  case N_DATA|N_EXT:    case N_WEAKD:   return N_DATA;
        case N_BSS:   case N_BSS |N_EXT:    case N_WEAKB:   return N_BSS;
        case N_SETA:  case N_SETA|N_EXT:                    return N_SETA;
        case N_SETT:  case N_SETT|N_EXT:                    return N_SETT;
        case N_SETD:  case N_SETD|N_EXT:                    return N_SETD;

        default:
          return type;
    }
}

/* find a sym name given its value, in a section number */
static const char *find_sym_with_value_and_sec_number(long value, int sec, int *offset)
{
    int i, ret = -1;
        
    for (i = 0; i < nb_syms; i++) {
        if (    !(symtab[i].n_type & N_STAB)
            &&  type_to_sec_number(symtab[i].n_type) == sec
            &&  symtab[i].st_value <= value
            &&  (   ret < 0
                 || symtab[i].st_value >= symtab[ret].st_value)) {
            ret = i;
        }
    }
    if (ret < 0) {
        *offset = 0;
        return 0;
    }
    *offset = value - symtab[ret].st_value;
    return get_sym_name(&symtab[ret]);
}

static const char *get_rel_sym_name_and_addend(EXE_RELOC *rel, int *sslide)
{
    int sec;
    int off;

    *sslide = 0;

    if (rel->r_extern)
    {
        /* ignore debug sym */
        if (symtab[rel->r_symbolnum].n_type & N_STAB)
            return 0;

        /* The intruction contains the addend. */
        off = *(uint32_t *)(text + rel->r_address);
        if (rel->r_pcrel)
            off += rel->r_address;
        *sslide = off;
        return get_sym_name(&symtab[rel->r_symbolnum]);
    }
    if (rel->r_symbolnum == 0xffffff)
        return 0;

    sec = rel->r_symbolnum & ~N_EXT;
    /* sanity */
    switch (sec)
    {
        case N_TEXT: case N_DATA: case N_BSS: case N_ABS: break;
        default: error("invalid section %d", sec);
    }

    /* The intruction contains the addend. */
    off = *(uint32_t *)(text + rel->r_address);
    if (rel->r_pcrel)
        off += rel->r_address;
                        
    /* search it in the full symbol list, if not found */
    return find_sym_with_value_and_sec_number(off, sec, sslide);
}

/* Used by dyngen common code */
static const char * get_rel_sym_name(EXE_RELOC *rel)
{
    int ignored;
    return get_rel_sym_name_and_addend(rel, &ignored);
}

/* Used by dyngen common code */
static host_ulong get_rel_offset(EXE_RELOC *rel)
{
    return rel->r_address;
}

/* load an a.out object file */
int load_object(const char *filename)
{
    FILE *pf;
    long file_size;
    unsigned i;
    EXE_SYM *dst_sym;
    struct nlist *src_sym;

    /*
     * Open the file and validate the header.
     */
    pf = fopen(filename, "rb");
    if (!pf)
        error("can't open file '%s'", filename);

    /* we're optimistic, read the entire file first. */
    if (fseek(pf, 0, SEEK_END) != 0)
      error("Input file '%s' is not seekable", filename);
    file_size = ftell(pf);
    fseek(pf, 0L, SEEK_SET);

    aout_hdr = malloc(file_size + 1);
    if (!aout_hdr)
        error("malloc(%ld) failed", file_size + 1);
    if (fread(aout_hdr, 1, file_size, pf) != file_size)
        error("error reading '%s'", filename);
    fclose(pf);

    /* validate the header. */
    if (N_MAGIC(*aout_hdr) != OMAGIC)
        error("unknown magic: %lo", N_MAGIC(*aout_hdr));
    if (N_MACHTYPE(*aout_hdr) != M_386 && N_MACHTYPE(*aout_hdr) != 0)
        error("unsupported machtype: %d", N_MACHTYPE(*aout_hdr));

    /* setup globals. */
    strtab = (char *)((uint8_t *)aout_hdr + N_STROFF(*aout_hdr));
    symtab_std = (struct nlist *)((uint8_t *)aout_hdr + N_SYMOFF(*aout_hdr));

    relocs = (struct relocation_info *)((uint8_t *)aout_hdr + N_TRELOFF(*aout_hdr));
    nb_syms = aout_hdr->a_syms / sizeof(struct nlist);
    text_shndx = 1;
    text = (uint8_t *)aout_hdr + N_TXTOFF(*aout_hdr);
    nb_relocs = aout_hdr->a_trsize / sizeof(relocs[0]);

    /*
     * Now transform the symtab, to an extended version, with the sym size, and the C name
     */
    src_sym = symtab_std;
    dst_sym = symtab = malloc(sizeof(EXE_SYM) * nb_syms);
    if (!dst_sym)
        error("malloc(%zd) failed", sizeof(EXE_SYM) * nb_syms);
    for (i = 0; i < nb_syms; i++, src_sym++, dst_sym++) {
        struct nlist *sym_next = NULL;
        struct nlist *sym_cur;
        unsigned sec;
        unsigned j;

        /* copy the symbol and find the name. */
        dst_sym->n_un.n_strx = src_sym->n_un.n_strx;
        dst_sym->n_type = src_sym->n_type;
        dst_sym->n_other = src_sym->n_other;
        dst_sym->n_desc = src_sym->n_desc;
        dst_sym->st_value = src_sym->n_value;
        dst_sym->st_size = 0;
        if (src_sym->n_type & N_STAB)
            continue; /* skip debug symbols. */

        /* Find the following symbol in order to get the current symbol size */
        sec = type_to_sec_number(dst_sym->n_type);
        for (j = 0, sym_cur = symtab_std; j < nb_syms; j++, sym_cur++) {
            if (    type_to_sec_number(sym_cur->n_type) != sec
                ||  (sym_cur->n_type & N_STAB)
                ||  sym_cur->n_value <= dst_sym->st_value)
                continue;
            if (     sym_next
                &&   sym_next->n_value <= sym_cur->n_value)
                 continue;
            /* good one */
            sym_next = sym_cur;
        }
        if (sym_next)
            dst_sym->st_size = sym_next->n_value - dst_sym->st_value;
        else
            dst_sym->st_size = aout_hdr->a_text - dst_sym->st_value;
    }
        
    return 0;
}

#endif /* CONFIG_FORMAT_AOUT */


void get_reloc_expr(char *name, int name_size, const char *sym_name)
{
    const char *p;

    if (strstart(sym_name, "__op_param", &p)) {
        snprintf(name, name_size, "param%s", p);
    } else if (strstart(sym_name, "__op_gen_label", &p)) {
        snprintf(name, name_size, "gen_labels[param%s]", p);
    } else {
#ifdef HOST_SPARC
        if (sym_name[0] == '.')
            snprintf(name, name_size,
                     "(long)(&__dot_%s)",
                     sym_name + 1);
        else
#endif
            snprintf(name, name_size, "(long)(&%s)", sym_name);
    }
}

#ifdef HOST_IA64

#define PLT_ENTRY_SIZE  16      /* 1 bundle containing "brl" */

struct plt_entry {
    struct plt_entry *next;
    const char *name;
    unsigned long addend;
} *plt_list;

static int
get_plt_index (const char *name, unsigned long addend)
{
    struct plt_entry *plt, *prev= NULL;
    int index = 0;

    /* see if we already have an entry for this target: */
    for (plt = plt_list; plt; ++index, prev = plt, plt = plt->next)
        if (strcmp(plt->name, name) == 0 && plt->addend == addend)
            return index;

    /* nope; create a new PLT entry: */

    plt = malloc(sizeof(*plt));
    if (!plt) {
        perror("malloc");
        exit(1);
    }
    memset(plt, 0, sizeof(*plt));
    plt->name = strdup(name);
    plt->addend = addend;

    /* append to plt-list: */
    if (prev)
        prev->next = plt;
    else
        plt_list = plt;
    return index;
}

#endif

#ifdef HOST_ARM

int arm_emit_ldr_info(const char *name, unsigned long start_offset,
                      FILE *outfile, uint8_t *p_start, uint8_t *p_end,
                      ELF_RELOC *relocs, int nb_relocs)
{
    uint8_t *p;
    uint32_t insn;
    int offset, min_offset, pc_offset, data_size, spare, max_pool;
    uint8_t data_allocated[1024];
    unsigned int data_index;
    int type;
    
    memset(data_allocated, 0, sizeof(data_allocated));
    
    p = p_start;
    min_offset = p_end - p_start;
    spare = 0x7fffffff;
    while (p < p_start + min_offset) {
        insn = get32((uint32_t *)p);
        /* TODO: Armv5e ldrd.  */
        /* TODO: VFP load.  */
        if ((insn & 0x0d5f0000) == 0x051f0000) {
            /* ldr reg, [pc, #im] */
            offset = insn & 0xfff;
            if (!(insn & 0x00800000))
                offset = -offset;
            max_pool = 4096;
            type = 0;
        } else if ((insn & 0x0e5f0f00) == 0x0c1f0100) {
            /* FPA ldf.  */
            offset = (insn & 0xff) << 2;
            if (!(insn & 0x00800000))
                offset = -offset;
            max_pool = 1024;
            type = 1;
        } else if ((insn & 0x0fff0000) == 0x028f0000) {
            /* Some gcc load a doubleword immediate with
               add regN, pc, #imm
               ldmia regN, {regN, regM}
               Hope and pray the compiler never generates somethin like
               add reg, pc, #imm1; ldr reg, [reg, #-imm2]; */
            int r;

            r = (insn & 0xf00) >> 7;
            offset = ((insn & 0xff) >> r) | ((insn & 0xff) << (32 - r));
            max_pool = 1024;
            type = 2;
        } else {
            max_pool = 0;
            type = -1;
        }
        if (type >= 0) {
            /* PC-relative load needs fixing up.  */
            if (spare > max_pool - offset)
                spare = max_pool - offset;
            if ((offset & 3) !=0)
                error("%s:%04x: pc offset must be 32 bit aligned", 
                      name, start_offset + p - p_start);
            if (offset < 0)
                error("%s:%04x: Embedded literal value",
                      name, start_offset + p - p_start);
            pc_offset = p - p_start + offset + 8;
            if (pc_offset <= (p - p_start) || 
                pc_offset >= (p_end - p_start))
                error("%s:%04x: pc offset must point inside the function code", 
                      name, start_offset + p - p_start);
            if (pc_offset < min_offset)
                min_offset = pc_offset;
            if (outfile) {
                /* The intruction position */
                fprintf(outfile, "    arm_ldr_ptr->ptr = gen_code_ptr + %d;\n", 
                        p - p_start);
                /* The position of the constant pool data.  */
                data_index = ((p_end - p_start) - pc_offset) >> 2;
                fprintf(outfile, "    arm_ldr_ptr->data_ptr = arm_data_ptr - %d;\n", 
                        data_index);
                fprintf(outfile, "    arm_ldr_ptr->type = %d;\n", type);
                fprintf(outfile, "    arm_ldr_ptr++;\n");
            }
        }
        p += 4;
    }

    /* Copy and relocate the constant pool data.  */
    data_size = (p_end - p_start) - min_offset;
    if (data_size > 0 && outfile) {
        spare += min_offset;
        fprintf(outfile, "    arm_data_ptr -= %d;\n", data_size >> 2);
        fprintf(outfile, "    arm_pool_ptr -= %d;\n", data_size);
        fprintf(outfile, "    if (arm_pool_ptr > gen_code_ptr + %d)\n"
                         "        arm_pool_ptr = gen_code_ptr + %d;\n",
                         spare, spare);

        data_index = 0;
        for (pc_offset = min_offset;
             pc_offset < p_end - p_start;
             pc_offset += 4) {

            ELF_RELOC *rel;
            int i, addend, type;
            const char *sym_name;
            char relname[1024];

            /* data value */
            addend = get32((uint32_t *)(p_start + pc_offset));
            relname[0] = '\0';
            for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                if (rel->r_offset == (pc_offset + start_offset)) {
                    sym_name = get_rel_sym_name(rel);
                    /* the compiler leave some unnecessary references to the code */
                    get_reloc_expr(relname, sizeof(relname), sym_name);
                    type = ELF32_R_TYPE(rel->r_info);
                    if (type != R_ARM_ABS32)
                        error("%s: unsupported data relocation", name);
                    break;
                }
            }
            fprintf(outfile, "    arm_data_ptr[%d] = 0x%x",
                    data_index, addend);
            if (relname[0] != '\0')
                fprintf(outfile, " + %s", relname);
            fprintf(outfile, ";\n");

            data_index++;
        }
    }

    if (p == p_start)
        goto arm_ret_error;
    p -= 4;
    insn = get32((uint32_t *)p);
    /* The last instruction must be an ldm instruction.  There are several
       forms generated by gcc:
        ldmib sp, {..., pc}  (implies a sp adjustment of +4)
        ldmia sp, {..., pc}
        ldmea fp, {..., pc} */
    if ((insn & 0xffff8000) == 0xe99d8000) {
        if (outfile) {
            fprintf(outfile,
                    "    *(uint32_t *)(gen_code_ptr + %d) = 0xe28dd004;\n",
                    p - p_start);
        }
        p += 4;
    } else if ((insn & 0xffff8000) != 0xe89d8000
        && (insn & 0xffff8000) != 0xe91b8000) {
    arm_ret_error:
        if (!outfile)
            printf("%s: invalid epilog\n", name);
    }
    return p - p_start;
}
#endif


#define MAX_ARGS 3

/* generate op code */
void gen_code(const char *name, host_ulong offset, host_ulong size, 
              FILE *outfile, int gen_switch)
{
    int copy_size = 0;
    uint8_t *p_start, *p_end;
    host_ulong start_offset;
    int nb_args, i, n;
    uint8_t args_present[MAX_ARGS];
    const char *sym_name, *p;
    EXE_RELOC *rel;

    /* Compute exact size excluding prologue and epilogue instructions.
     * Increment start_offset to skip epilogue instructions, then compute
     * copy_size the indicate the size of the remaining instructions (in
     * bytes).
     */
    p_start = text + offset;
    p_end = p_start + size;
    start_offset = offset;
#if defined(HOST_I386) || defined(HOST_X86_64)
#if defined(CONFIG_FORMAT_COFF) || defined(CONFIG_FORMAT_AOUT) || defined(CONFIG_FORMAT_MACH)
    {
        uint8_t *p;
        p = p_end - 1;
        if (p == p_start)
            error("empty code for %s", name);
        while (*p != 0xc3) {
            p--;
            if (p <= p_start)
                error("ret or jmp expected at the end of %s", name);
        }
        copy_size = p - p_start;
    }
#else
    {
        int len;
        len = p_end - p_start;
        if (len == 0)
            error("empty code for %s", name);
        if (p_end[-1] == 0xc3) {
            len--;
        } else {
            error("ret or jmp expected at the end of %s", name);
        }
        copy_size = len;
    }
#endif    
#elif defined(HOST_PPC)
    {
        uint8_t *p;
        p = (void *)(p_end - 4);
        if (p == p_start)
            error("empty code for %s", name);
        if (get32((uint32_t *)p) != 0x4e800020)
            error("blr expected at the end of %s", name);
        copy_size = p - p_start;
    }
#elif defined(HOST_S390)
    {
        uint8_t *p;
        p = (void *)(p_end - 2);
        if (p == p_start)
            error("empty code for %s", name);
        if (get16((uint16_t *)p) != 0x07fe && get16((uint16_t *)p) != 0x07f4)
            error("br %%r14 expected at the end of %s", name);
        copy_size = p - p_start;
    }
#elif defined(HOST_ALPHA)
    {
        uint8_t *p;
        p = p_end - 4;
#if 0
        /* XXX: check why it occurs */
        if (p == p_start)
            error("empty code for %s", name);
#endif
        if (get32((uint32_t *)p) != 0x6bfa8001)
            error("ret expected at the end of %s", name);
        copy_size = p - p_start;            
    }
#elif defined(HOST_IA64)
    {
        uint8_t *p;
        p = (void *)(p_end - 4);
        if (p == p_start)
            error("empty code for %s", name);
        /* br.ret.sptk.many b0;; */
        /* 08 00 84 00 */
        if (get32((uint32_t *)p) != 0x00840008)
            error("br.ret.sptk.many b0;; expected at the end of %s", name);
        copy_size = p_end - p_start;
    }
#elif defined(HOST_SPARC)
    {
#define INSN_SAVE       0x9de3a000
#define INSN_RET        0x81c7e008
#define INSN_RETL       0x81c3e008
#define INSN_RESTORE    0x81e80000
#define INSN_RETURN     0x81cfe008
#define INSN_NOP        0x01000000
#define INSN_ADD_SP     0x9c03a000 /* add %sp, nn, %sp */
#define INSN_SUB_SP     0x9c23a000 /* sub %sp, nn, %sp */

        uint32_t start_insn, end_insn1, end_insn2;
        uint8_t *p;
        p = (void *)(p_end - 8);
        if (p <= p_start)
            error("empty code for %s", name);
        start_insn = get32((uint32_t *)(p_start + 0x0));
        end_insn1 = get32((uint32_t *)(p + 0x0));
        end_insn2 = get32((uint32_t *)(p + 0x4));
        if (((start_insn & ~0x1fff) == INSN_SAVE) ||
            (start_insn & ~0x1fff) == INSN_ADD_SP) {
            p_start += 0x4;
            start_offset += 0x4;
            if (end_insn1 == INSN_RET && end_insn2 == INSN_RESTORE)
                /* SPARC v7: ret; restore; */ ;
            else if (end_insn1 == INSN_RETURN && end_insn2 == INSN_NOP)
                /* SPARC v9: return; nop; */ ;
            else if (end_insn1 == INSN_RETL && (end_insn2 & ~0x1fff) == INSN_SUB_SP)
                /* SPARC v7: retl; sub %sp, nn, %sp; */ ;
            else

                error("ret; restore; not found at end of %s", name);
        } else if (end_insn1 == INSN_RETL && end_insn2 == INSN_NOP) {
            ;
        } else {
            error("No save at the beginning of %s", name);
        }
#if 0
        /* Skip a preceeding nop, if present.  */
        if (p > p_start) {
            skip_insn = get32((uint32_t *)(p - 0x4));
            if (skip_insn == INSN_NOP)
                p -= 4;
        }
#endif
        copy_size = p - p_start;
    }
#elif defined(HOST_SPARC64)
    {
#define INSN_SAVE       0x9de3a000
#define INSN_RET        0x81c7e008
#define INSN_RETL       0x81c3e008
#define INSN_RESTORE    0x81e80000
#define INSN_RETURN     0x81cfe008
#define INSN_NOP        0x01000000
#define INSN_ADD_SP     0x9c03a000 /* add %sp, nn, %sp */
#define INSN_SUB_SP     0x9c23a000 /* sub %sp, nn, %sp */

        uint32_t start_insn, end_insn1, end_insn2, skip_insn;
        uint8_t *p;
        p = (void *)(p_end - 8);
#if 0
        /* XXX: check why it occurs */
        if (p <= p_start)
            error("empty code for %s", name);
#endif
        start_insn = get32((uint32_t *)(p_start + 0x0));
        end_insn1 = get32((uint32_t *)(p + 0x0));
        end_insn2 = get32((uint32_t *)(p + 0x4));
        if (((start_insn & ~0x1fff) == INSN_SAVE) ||
            (start_insn & ~0x1fff) == INSN_ADD_SP) {
            p_start += 0x4;
            start_offset += 0x4;
            if (end_insn1 == INSN_RET && end_insn2 == INSN_RESTORE)
                /* SPARC v7: ret; restore; */ ;
            else if (end_insn1 == INSN_RETURN && end_insn2 == INSN_NOP)
                /* SPARC v9: return; nop; */ ;
            else if (end_insn1 == INSN_RETL && (end_insn2 & ~0x1fff) == INSN_SUB_SP)
                /* SPARC v7: retl; sub %sp, nn, %sp; */ ;
            else

                error("ret; restore; not found at end of %s", name);
        } else if (end_insn1 == INSN_RETL && end_insn2 == INSN_NOP) {
            ;
        } else {
            error("No save at the beginning of %s", name);
        }
        
        /* Skip a preceeding nop, if present.  */
        if (p > p_start) {
            skip_insn = get32((uint32_t *)(p - 0x4));
            if (skip_insn == 0x01000000)
                p -= 4;
        }
        
        copy_size = p - p_start;
    }
#elif defined(HOST_ARM)
    {
        uint32_t insn;

        if ((p_end - p_start) <= 16)
            error("%s: function too small", name);
        if (get32((uint32_t *)p_start) != 0xe1a0c00d ||
            (get32((uint32_t *)(p_start + 4)) & 0xffff0000) != 0xe92d0000 ||
            get32((uint32_t *)(p_start + 8)) != 0xe24cb004)
            error("%s: invalid prolog", name);
        p_start += 12;
        start_offset += 12;
        insn = get32((uint32_t *)p_start);
        if ((insn & 0xffffff00) == 0xe24dd000) {
            /* Stack adjustment.  Assume op uses the frame pointer.  */
            p_start -= 4;
            start_offset -= 4;
        }
        copy_size = arm_emit_ldr_info(name, start_offset, NULL, p_start, p_end, 
                                      relocs, nb_relocs);
    }
#elif defined(HOST_M68K)
    {
        uint8_t *p;
        p = (void *)(p_end - 2);
        if (p == p_start)
            error("empty code for %s", name);
        /* remove NOP's, probably added for alignment */
        while ((get16((uint16_t *)p) == 0x4e71) &&
               (p>p_start)) 
            p -= 2;
        if (get16((uint16_t *)p) != 0x4e75)
            error("rts expected at the end of %s", name);
        copy_size = p - p_start;
    }
#else
#error unsupported CPU
#endif

    /* compute the number of arguments by looking at the relocations */
    for(i = 0;i < MAX_ARGS; i++)
        args_present[i] = 0;

    for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
        host_ulong offset = get_rel_offset(rel);
        if (offset >= start_offset &&
            offset < start_offset + (p_end - p_start)) {
            sym_name = get_rel_sym_name(rel);
            if(!sym_name)
                continue;
            if (strstart(sym_name, "__op_param", &p) ||
                strstart(sym_name, "__op_gen_label", &p)) {
                n = strtoul(p, NULL, 10);
                if (n > MAX_ARGS)
                    error("too many arguments in %s", name);
                args_present[n - 1] = 1;
            }
        }
    }
    
    nb_args = 0;
    while (nb_args < MAX_ARGS && args_present[nb_args])
        nb_args++;
    for(i = nb_args; i < MAX_ARGS; i++) {
        if (args_present[i])
            error("inconsistent argument numbering in %s", name);
    }

    if (gen_switch == 2) {
        fprintf(outfile, "DEF(%s, %d, %d)\n", name + 3, nb_args, copy_size);
    } else if (gen_switch == 1) {

        /* output C code */
        fprintf(outfile, "case INDEX_%s: {\n", name);
        if (nb_args > 0) {
            fprintf(outfile, "    long ");
            for(i = 0; i < nb_args; i++) {
                if (i != 0)
                    fprintf(outfile, ", ");
                fprintf(outfile, "param%d", i + 1);
            }
            fprintf(outfile, ";\n");
        }
#if defined(HOST_IA64)
        fprintf(outfile, "    extern char %s;\n", name);
#else
        fprintf(outfile, "    extern void %s();\n", name);
#endif

        for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
            host_ulong offset = get_rel_offset(rel);
            if (offset >= start_offset &&
                offset < start_offset + (p_end - p_start)) {
                sym_name = get_rel_sym_name(rel);
                if(!sym_name)
                    continue;
                if (*sym_name && 
#ifdef VBOX
                    !strstart(sym_name, "remR3PhysWrite", NULL) &&
                    !strstart(sym_name, "remR3PhysRead", NULL) &&
#endif
                    !strstart(sym_name, "__op_param", NULL) &&
                    !strstart(sym_name, "__op_jmp", NULL) &&
                    !strstart(sym_name, "__op_gen_label", NULL)) {
#if defined(HOST_SPARC)
                    if (sym_name[0] == '.') {
                        fprintf(outfile,
                                "extern char __dot_%s __asm__(\"%s\");\n",
                                sym_name+1, sym_name);
                        continue;
                    }
#endif
#if defined(__APPLE__)
/* set __attribute((unused)) on darwin because we wan't to avoid warning when we don't use the symbol */
                    fprintf(outfile, "extern char %s __attribute__((unused));\n", sym_name);
#elif defined(HOST_IA64)
                        if (ELF64_R_TYPE(rel->r_info) != R_IA64_PCREL21B)
                                /*
                                 * PCREL21 br.call targets generally
                                 * are out of range and need to go
                                 * through an "import stub".
                                 */
                                fprintf(outfile, "    extern char %s;\n",
                                        sym_name);
#else
                    /* don't include memcpy here as this external reference wouldn't work anyway! */
                    if (strcmp(sym_name, "memcpy"))
                        fprintf(outfile, "extern char %s;\n", sym_name);
#endif
                }
            }
        }

        fprintf(outfile, "    memcpy(gen_code_ptr, (void *)((char *)&%s+%d), %d);\n",
                                        name, (int)(start_offset - offset), copy_size);

        /* emit code offset information */
        {
            EXE_SYM *sym;
            const char *sym_name, *p;
            unsigned long val;
            int n;

            for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
                sym_name = get_sym_name(sym);
                if (strstart(sym_name, "__op_label", &p)) {
                    uint8_t *ptr;
                    unsigned long offset;
                    
                    /* test if the variable refers to a label inside
                       the code we are generating */
#ifdef CONFIG_FORMAT_COFF
                    if (sym->st_shndx == text_shndx) {
                        ptr = sdata[coff_text_shndx];
                    } else if (sym->st_shndx == data_shndx) {
                        ptr = sdata[coff_data_shndx];
                    } else {
                        ptr = NULL;
                    }
#elif defined(CONFIG_FORMAT_MACH)
                    if(!sym->n_sect)
                        continue;
                    ptr = sdata[sym->n_sect-1];
#elif defined(CONFIG_FORMAT_AOUT)
                    switch (type_to_sec_number(sym->n_type))
                    {
                        case N_TEXT:    ptr = (uint8_t *)aout_hdr + N_TXTOFF(*aout_hdr); break;
                        case N_DATA:    ptr = (uint8_t *)aout_hdr + N_DATOFF(*aout_hdr); break;
                        default:        ptr = NULL;
                    }
#else
                    ptr = sdata[sym->st_shndx];
#endif
                    if (!ptr)
                        error("__op_labelN in invalid section");
                    offset = sym->st_value;
#ifdef CONFIG_FORMAT_MACH
                    offset -= section_hdr[sym->n_sect-1].addr;
#elif defined(CONFIG_FORMAT_AOUT)
                    if (type_to_sec_number(sym->n_type) == N_DATA)
                        offset -= aout_hdr->a_text;
#endif
                    val = *(unsigned long *)(ptr + offset);
#ifdef ELF_USES_RELOCA
                    {
                        int reloc_shndx, nb_relocs1, j;

                        /* try to find a matching relocation */
                        reloc_shndx = find_reloc(sym->st_shndx);
                        if (reloc_shndx) {
                            nb_relocs1 = shdr[reloc_shndx].sh_size / 
                                shdr[reloc_shndx].sh_entsize;
                            rel = (ELF_RELOC *)sdata[reloc_shndx];
                            for(j = 0; j < nb_relocs1; j++) {
                                if (rel->r_offset == offset) {
                                    val = rel->r_addend;
                                    break;
                                }
                                rel++;
                            }
                        }
                    }
#endif                    
                    if (val >= start_offset && val <= start_offset + copy_size) {
                        n = strtol(p, NULL, 10);
                        fprintf(outfile, "    label_offsets[%d] = %ld + (gen_code_ptr - gen_code_buf);\n", n, (long)(val - start_offset));
                    }
                }
            }
        }

        /* load parameres in variables */
        for(i = 0; i < nb_args; i++) {
            fprintf(outfile, "    param%d = *opparam_ptr++;\n", i + 1);
        }

        /* patch relocations */
#if defined(HOST_I386) 
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                host_ulong offset = get_rel_offset(rel);
                if (offset >= start_offset &&
                    offset < start_offset + copy_size) {
#if defined(CONFIG_FORMAT_AOUT) || defined(CONFIG_FORMAT_MACH)
                    sym_name = get_rel_sym_name_and_addend(rel, &addend);
#else
                    sym_name = get_rel_sym_name(rel);
#endif
                    if (!sym_name)
                        continue;
                    reloc_offset = offset - start_offset;
                    if (strstart(sym_name, "__op_jmp", &p)) {
                        int n;
                        n = strtol(p, NULL, 10);
                        /* __op_jmp relocations are done at
                           runtime to do translated block
                           chaining: the offset of the instruction
                           needs to be stored */
                        fprintf(outfile, "    jmp_offsets[%d] = %d + (gen_code_ptr - gen_code_buf);\n",
                                n, reloc_offset);
                        continue;
                    }

                    get_reloc_expr(name, sizeof(name), sym_name);
#if !defined(CONFIG_FORMAT_AOUT) && !defined(CONFIG_FORMAT_MACH)
                    addend = get32((uint32_t *)(text + offset));
#endif
#ifdef CONFIG_FORMAT_ELF
                    type = ELF32_R_TYPE(rel->r_info);
                    switch(type) {
                    case R_386_32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_386_PC32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d;\n", 
                                reloc_offset, name, reloc_offset, addend);
                        break;
                    default:
                        error("unsupported i386 relocation (%d)", type);
                    }
#elif defined(CONFIG_FORMAT_COFF)
                    {
                        char *temp_name;
                        int j;
                        EXE_SYM *sym;
                        temp_name = get_sym_name(symtab + *(uint32_t *)(rel->r_reloc->r_symndx));
                        if (!strcmp(temp_name, ".data")) {
                            for (j = 0, sym = symtab; j < nb_syms; j++, sym++) {
                                if (strstart(sym->st_name, sym_name, NULL)) {
                                    addend -= sym->st_value;
                                }
                            }
                        }
                    }
                    type = rel->r_type;
                    switch(type) {
                    case DIR32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case DISP32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d -4;\n", 
                                reloc_offset, name, reloc_offset, addend);
                        break;
                    default:
                        error("unsupported i386 relocation (%d)", type);
                    }
#elif defined(CONFIG_FORMAT_AOUT) || defined(CONFIG_FORMAT_MACH)
                    if (rel->r_pcrel) {
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d;\n",
                                offset - start_offset, name, offset - start_offset, addend);
                    } else {
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n",
                                offset - start_offset, name, addend);
                    }
                    (void)type;
#else
#error unsupport object format
#endif
                }
                }
            }
#elif defined(HOST_X86_64)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                if (rel->r_offset >= start_offset &&
                    rel->r_offset < start_offset + copy_size) {
                    sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                    get_reloc_expr(name, sizeof(name), sym_name);
                    type = ELF32_R_TYPE(rel->r_info);
                    addend = rel->r_addend;
                    reloc_offset = rel->r_offset - start_offset;
                    switch(type) {
                    case R_X86_64_32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (uint32_t)%s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_X86_64_32S:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (int32_t)%s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_X86_64_PC32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %d) + %d;\n", 
                                reloc_offset, name, reloc_offset, addend);
                        break;
#ifdef VBOX /** @todo Re-check the sanity of this */
                    case R_X86_64_64:
                        fprintf(outfile, "    *(uint64_t *)(gen_code_ptr + %d) = (uint64_t)%s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
#endif 
                    default:
                        error("unsupported X86_64 relocation (%d)", type);
                    }
                }
                }
            }
#elif defined(HOST_PPC)
            {
#ifdef CONFIG_FORMAT_ELF
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset &&
                        rel->r_offset < start_offset + copy_size) {
                        sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                        reloc_offset = rel->r_offset - start_offset;
                        if (strstart(sym_name, "__op_jmp", &p)) {
                            int n;
                            n = strtol(p, NULL, 10);
                            /* __op_jmp relocations are done at
                               runtime to do translated block
                               chaining: the offset of the instruction
                               needs to be stored */
                            fprintf(outfile, "    jmp_offsets[%d] = %d + (gen_code_ptr - gen_code_buf);\n",
                                    n, reloc_offset);
                            continue;
                        }
                        
                        get_reloc_expr(name, sizeof(name), sym_name);
                        type = ELF32_R_TYPE(rel->r_info);
                        addend = rel->r_addend;
                        switch(type) {
                        case R_PPC_ADDR32:
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_ADDR16_LO:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d);\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_ADDR16_HI:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d) >> 16;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_ADDR16_HA:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = (%s + %d + 0x8000) >> 16;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_PPC_REL24:
                            /* warning: must be at 32 MB distancy */
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | ((%s - (long)(gen_code_ptr + %d) + %d) & 0x03fffffc);\n", 
                                    reloc_offset, reloc_offset, name, reloc_offset, addend);
                            break;
                        default:
                            error("unsupported powerpc relocation (%d)", type);
                        }
                    }
                }
#elif defined(CONFIG_FORMAT_MACH)
                                struct scattered_relocation_info *scarel;
                                struct relocation_info * rel;
                                char final_sym_name[256];
                                const char *sym_name;
                                const char *p;
                                int slide, sslide;
                                int i;
        
                                for(i = 0, rel = relocs; i < nb_relocs; i++, rel++) {
                                        unsigned int offset, length, value = 0;
                                        unsigned int type, pcrel, isym = 0;
                                        unsigned int usesym = 0;
                                
                                        if(R_SCATTERED & rel->r_address) {
                                                scarel = (struct scattered_relocation_info*)rel;
                                                offset = (unsigned int)scarel->r_address;
                                                length = scarel->r_length;
                                                pcrel = scarel->r_pcrel;
                                                type = scarel->r_type;
                                                value = scarel->r_value;
                                        } else {
                                                value = isym = rel->r_symbolnum;
                                                usesym = (rel->r_extern);
                                                offset = rel->r_address;
                                                length = rel->r_length;
                                                pcrel = rel->r_pcrel;
                                                type = rel->r_type;
                                        }
                                
                                        slide = offset - start_offset;
                
                                        if (!(offset >= start_offset && offset < start_offset + size)) 
                                                continue;  /* not in our range */

                                        sym_name = get_reloc_name(rel, &sslide);
                                        
                                        if(usesym && symtab[isym].n_type & N_STAB)
                                                continue; /* don't handle STAB (debug sym) */
                                        
                                        if (sym_name && strstart(sym_name, "__op_jmp", &p)) {
                                                int n;
                                                n = strtol(p, NULL, 10);
                                                fprintf(outfile, "    jmp_offsets[%d] = %d + (gen_code_ptr - gen_code_buf);\n",
                                                        n, slide);
                                                continue; /* Nothing more to do */
                                        }
                                        
                                        if(!sym_name)
                                        {
                                                fprintf(outfile, "/* #warning relocation not handled in %s (value 0x%x, %s, offset 0x%x, length 0x%x, %s, type 0x%x) */\n",
                                                           name, value, usesym ? "use sym" : "don't use sym", offset, length, pcrel ? "pcrel":"", type);
                                                continue; /* dunno how to handle without final_sym_name */
                                        }
                                                                                                           
                                        get_reloc_expr(final_sym_name, sizeof(final_sym_name), 
                                                       sym_name);
                                        switch(type) {
                                        case PPC_RELOC_BR24:
                                            if (!strstart(sym_name,"__op_gen_label",&p)) {
                                                fprintf(outfile, "{\n");
                                                fprintf(outfile, "    uint32_t imm = *(uint32_t *)(gen_code_ptr + %d) & 0x3fffffc;\n", slide);
                                                fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | ((imm + ((long)%s - (long)gen_code_ptr) + %d) & 0x03fffffc);\n", 
                                                                                        slide, slide, name, sslide );
                                                fprintf(outfile, "}\n");
                                        } else {
                                                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = (*(uint32_t *)(gen_code_ptr + %d) & ~0x03fffffc) | (((long)%s - (long)gen_code_ptr - %d) & 0x03fffffc);\n",
                                                                                        slide, slide, final_sym_name, slide);
                                        }
                                                break;
                                        case PPC_RELOC_HI16:
                                                fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d + 2) = (%s + %d) >> 16;\n", 
                                                        slide, final_sym_name, sslide);
                                                break;
                                        case PPC_RELOC_LO16:
                                                fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d + 2) = (%s + %d);\n", 
                                        slide, final_sym_name, sslide);
                            break;
                                        case PPC_RELOC_HA16:
                                                fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d + 2) = (%s + %d + 0x8000) >> 16;\n", 
                                                        slide, final_sym_name, sslide);
                                                break;
                                default:
                                        error("unsupported powerpc relocation (%d)", type);
                                }
                        }
#else
#error unsupport object format
#endif
            }
#elif defined(HOST_S390)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset &&
                        rel->r_offset < start_offset + copy_size) {
                        sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                        get_reloc_expr(name, sizeof(name), sym_name);
                        type = ELF32_R_TYPE(rel->r_info);
                        addend = rel->r_addend;
                        reloc_offset = rel->r_offset - start_offset;
                        switch(type) {
                        case R_390_32:
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_390_16:
                            fprintf(outfile, "    *(uint16_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_390_8:
                            fprintf(outfile, "    *(uint8_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        default:
                            error("unsupported s390 relocation (%d)", type);
                        }
                    }
                }
            }
#elif defined(HOST_ALPHA)
            {
                for (i = 0, rel = relocs; i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset && rel->r_offset < start_offset + copy_size) {
                        int type;
                        long reloc_offset;

                        type = ELF64_R_TYPE(rel->r_info);
                        sym_name = strtab + symtab[ELF64_R_SYM(rel->r_info)].st_name;
                        reloc_offset = rel->r_offset - start_offset;
                        switch (type) {
                        case R_ALPHA_GPDISP:
                            /* The gp is just 32 bit, and never changes, so it's easiest to emit it
                               as an immediate instead of constructing it from the pv or ra.  */
                            fprintf(outfile, "    immediate_ldah(gen_code_ptr + %ld, gp);\n",
                                    reloc_offset);
                            fprintf(outfile, "    immediate_lda(gen_code_ptr + %ld, gp);\n",
                                    reloc_offset + (int)rel->r_addend);
                            break;
                        case R_ALPHA_LITUSE:
                            /* jsr to literal hint. Could be used to optimize to bsr. Ignore for
                               now, since some called functions (libc) need pv to be set up.  */
                            break;
                        case R_ALPHA_HINT:
                            /* Branch target prediction hint. Ignore for now.  Should be already
                               correct for in-function jumps.  */
                            break;
                        case R_ALPHA_LITERAL:
                            /* Load a literal from the GOT relative to the gp.  Since there's only a
                               single gp, nothing is to be done.  */
                            break;
                        case R_ALPHA_GPRELHIGH:
                            /* Handle fake relocations against __op_param symbol.  Need to emit the
                               high part of the immediate value instead.  Other symbols need no
                               special treatment.  */
                            if (strstart(sym_name, "__op_param", &p))
                                fprintf(outfile, "    immediate_ldah(gen_code_ptr + %ld, param%s);\n",
                                        reloc_offset, p);
                            break;
                        case R_ALPHA_GPRELLOW:
                            if (strstart(sym_name, "__op_param", &p))
                                fprintf(outfile, "    immediate_lda(gen_code_ptr + %ld, param%s);\n",
                                        reloc_offset, p);
                            break;
                        case R_ALPHA_BRSGP:
                            /* PC-relative jump. Tweak offset to skip the two instructions that try to
                               set up the gp from the pv.  */
                            fprintf(outfile, "    fix_bsr(gen_code_ptr + %ld, (uint8_t *) &%s - (gen_code_ptr + %ld + 4) + 8);\n",
                                    reloc_offset, sym_name, reloc_offset);
                            break;
                        default:
                            error("unsupported Alpha relocation (%d)", type);
                        }
                    }
                }
            }
#elif defined(HOST_IA64)
            {
                unsigned long sym_idx;
                long code_offset;
                char name[256];
                int type;
                long addend;

                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    sym_idx = ELF64_R_SYM(rel->r_info);
                    if (rel->r_offset < start_offset
                        || rel->r_offset >= start_offset + copy_size)
                        continue;
                    sym_name = (strtab + symtab[sym_idx].st_name);
                    code_offset = rel->r_offset - start_offset;
                    if (strstart(sym_name, "__op_jmp", &p)) {
                        int n;
                        n = strtol(p, NULL, 10);
                        /* __op_jmp relocations are done at
                           runtime to do translated block
                           chaining: the offset of the instruction
                           needs to be stored */
                        fprintf(outfile, "    jmp_offsets[%d] ="
                                "%ld + (gen_code_ptr - gen_code_buf);\n",
                                n, code_offset);
                        continue;
                    }
                    get_reloc_expr(name, sizeof(name), sym_name);
                    type = ELF64_R_TYPE(rel->r_info);
                    addend = rel->r_addend;
                    switch(type) {
                      case R_IA64_IMM64:
                          fprintf(outfile,
                                  "    ia64_imm64(gen_code_ptr + %ld, "
                                  "%s + %ld);\n",
                                  code_offset, name, addend);
                          break;
                      case R_IA64_LTOFF22X:
                      case R_IA64_LTOFF22:
                          fprintf(outfile, "    IA64_LTOFF(gen_code_ptr + %ld,"
                                  " %s + %ld, %d);\n",
                                  code_offset, name, addend,
                                  (type == R_IA64_LTOFF22X));
                          break;
                      case R_IA64_LDXMOV:
                          fprintf(outfile,
                                  "    ia64_ldxmov(gen_code_ptr + %ld,"
                                  " %s + %ld);\n", code_offset, name, addend);
                          break;

                      case R_IA64_PCREL21B:
                          if (strstart(sym_name, "__op_gen_label", NULL)) {
                              fprintf(outfile,
                                      "    ia64_imm21b(gen_code_ptr + %ld,"
                                      " (long) (%s + %ld -\n\t\t"
                                      "((long) gen_code_ptr + %ld)) >> 4);\n",
                                      code_offset, name, addend,
                                      code_offset & ~0xfUL);
                          } else {
                              fprintf(outfile,
                                      "    IA64_PLT(gen_code_ptr + %ld, "
                                      "%d);\t/* %s + %ld */\n",
                                      code_offset,
                                      get_plt_index(sym_name, addend),
                                      sym_name, addend);
                          }
                          break;
                      default:
                          error("unsupported ia64 relocation (0x%x)",
                                type);
                    }
                }
                fprintf(outfile, "    ia64_nop_b(gen_code_ptr + %d);\n",
                        copy_size - 16 + 2);
            }
#elif defined(HOST_SPARC)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset &&
                        rel->r_offset < start_offset + copy_size) {
                        sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
                        get_reloc_expr(name, sizeof(name), sym_name);
                        type = ELF32_R_TYPE(rel->r_info);
                        addend = rel->r_addend;
                        reloc_offset = rel->r_offset - start_offset;
                        switch(type) {
                        case R_SPARC_32:
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                    reloc_offset, name, addend);
                            break;
                        case R_SPARC_HI22:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3fffff) "
                                    " | (((%s + %d) >> 10) & 0x3fffff);\n",
                                    reloc_offset, reloc_offset, name, addend);
                            break;
                        case R_SPARC_LO10:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3ff) "
                                    " | ((%s + %d) & 0x3ff);\n",
                                    reloc_offset, reloc_offset, name, addend);
                            break;
                        case R_SPARC_WDISP30:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3fffffff) "
                                    " | ((((%s + %d) - (long)(gen_code_ptr + %d))>>2) "
                                    "    & 0x3fffffff);\n",
                                    reloc_offset, reloc_offset, name, addend,
                                    reloc_offset);
                            break;
                        case R_SPARC_WDISP22:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3fffff) "
                                    " | ((((%s + %d) - (long)(gen_code_ptr + %d))>>2) "
                                    "    & 0x3fffff);\n",
                                    rel->r_offset - start_offset,
                                    rel->r_offset - start_offset,
                                    name, addend,
                                    rel->r_offset - start_offset);
                            break;
                        default:
                            error("unsupported sparc relocation (%d)", type);
                        }
                    }
                }
            }
#elif defined(HOST_SPARC64)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                    if (rel->r_offset >= start_offset &&
                        rel->r_offset < start_offset + copy_size) {
                        sym_name = strtab + symtab[ELF64_R_SYM(rel->r_info)].st_name;
                        get_reloc_expr(name, sizeof(name), sym_name);
                        type = ELF32_R_TYPE(rel->r_info);
                        addend = rel->r_addend;
                        reloc_offset = rel->r_offset - start_offset;
                        switch(type) {
                        case R_SPARC_32:
                            fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n",
                                    reloc_offset, name, addend);
                            break;
                        case R_SPARC_HI22:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3fffff) "
                                    " | (((%s + %d) >> 10) & 0x3fffff);\n",
                                    reloc_offset, reloc_offset, name, addend);
                            break;
                        case R_SPARC_LO10:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3ff) "
                                    " | ((%s + %d) & 0x3ff);\n",
                                    reloc_offset, reloc_offset, name, addend);
                            break;
                        case R_SPARC_OLO10:
                            addend += ELF64_R_TYPE_DATA (rel->r_info);
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3ff) "
                                    " | ((%s + %d) & 0x3ff);\n",
                                    reloc_offset, reloc_offset, name, addend);
                            break;
                        case R_SPARC_WDISP30:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3fffffff) "
                                    " | ((((%s + %d) - (long)(gen_code_ptr + %d))>>2) "
                                    "    & 0x3fffffff);\n",
                                    reloc_offset, reloc_offset, name, addend,
                                    reloc_offset);
                            break;
                        case R_SPARC_WDISP22:
                            fprintf(outfile,
                                    "    *(uint32_t *)(gen_code_ptr + %d) = "
                                    "((*(uint32_t *)(gen_code_ptr + %d)) "
                                    " & ~0x3fffff) "
                                    " | ((((%s + %d) - (long)(gen_code_ptr + %d))>>2) "
                                    "    & 0x3fffff);\n",
                                    reloc_offset, reloc_offset, name, addend,
                                    reloc_offset);
                            break;
                        default:
                            error("unsupported sparc64 relocation (%d) for symbol %s", type, name);
                        }
                    }
                }
            }
#elif defined(HOST_ARM)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                uint32_t insn;

                insn = get32((uint32_t *)(p_start + 4));
                /* If prologue ends in sub sp, sp, #const then assume
                   op has a stack frame and needs the frame pointer.  */
                if ((insn & 0xffffff00) == 0xe24dd000) {
                    int i;
                    uint32_t opcode;
                    opcode = 0xe28db000; /* add fp, sp, #0.  */
#if 0
/* ??? Need to undo the extra stack adjustment at the end of the op.
   For now just leave the stack misaligned and hope it doesn't break anything
   too important.  */
                    if ((insn & 4) != 0) {
                        /* Preserve doubleword stack alignment.  */
                        fprintf(outfile,
                                "    *(uint32_t *)(gen_code_ptr + 4)= 0x%x;\n",
                                insn + 4);
                        opcode -= 4;
                    }
#endif
                    insn = get32((uint32_t *)(p_start - 4));
                    /* Calculate the size of the saved registers,
                       excluding pc.  */
                    for (i = 0; i < 15; i++) {
                        if (insn & (1 << i))
                            opcode += 4;
                    }
                    fprintf(outfile,
                            "    *(uint32_t *)gen_code_ptr = 0x%x;\n", opcode);
                }
                arm_emit_ldr_info(name, start_offset, outfile, p_start, p_end,
                                  relocs, nb_relocs);

                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                if (rel->r_offset >= start_offset &&
                    rel->r_offset < start_offset + copy_size) {
                    sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                    /* the compiler leave some unnecessary references to the code */
                    if (sym_name[0] == '\0')
                        continue;
                    get_reloc_expr(name, sizeof(name), sym_name);
                    type = ELF32_R_TYPE(rel->r_info);
                    addend = get32((uint32_t *)(text + rel->r_offset));
                    reloc_offset = rel->r_offset - start_offset;
                    switch(type) {
                    case R_ARM_ABS32:
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %d;\n", 
                                reloc_offset, name, addend);
                        break;
                    case R_ARM_PC24:
                    case R_ARM_JUMP24:
                    case R_ARM_CALL:
                        fprintf(outfile, "    arm_reloc_pc24((uint32_t *)(gen_code_ptr + %d), 0x%x, %s);\n", 
                                reloc_offset, addend, name);
                        break;
                    default:
                        error("unsupported arm relocation (%d)", type);
                    }
                }
                }
            }
#elif defined(HOST_M68K)
            {
                char name[256];
                int type;
                int addend;
                int reloc_offset;
                Elf32_Sym *sym;
                for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
                if (rel->r_offset >= start_offset &&
                    rel->r_offset < start_offset + copy_size) {
                    sym = &(symtab[ELFW(R_SYM)(rel->r_info)]);
                    sym_name = strtab + symtab[ELFW(R_SYM)(rel->r_info)].st_name;
                    get_reloc_expr(name, sizeof(name), sym_name);
                    type = ELF32_R_TYPE(rel->r_info);
                    addend = get32((uint32_t *)(text + rel->r_offset)) + rel->r_addend;
                    reloc_offset = rel->r_offset - start_offset;
                    switch(type) {
                    case R_68K_32:
                        fprintf(outfile, "    /* R_68K_32 RELOC, offset %x */\n", rel->r_offset) ;
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s + %#x;\n", 
                                reloc_offset, name, addend );
                        break;
                    case R_68K_PC32:
                        fprintf(outfile, "    /* R_68K_PC32 RELOC, offset %x */\n", rel->r_offset);
                        fprintf(outfile, "    *(uint32_t *)(gen_code_ptr + %d) = %s - (long)(gen_code_ptr + %#x) + %#x;\n", 
                                reloc_offset, name, reloc_offset, /*sym->st_value+*/ addend);
                        break;
                    default:
                        error("unsupported m68k relocation (%d)", type);
                    }
                }
                }
            }
#else
#error unsupported CPU
#endif
        fprintf(outfile, "    gen_code_ptr += %d;\n", copy_size);
        fprintf(outfile, "}\n");
        fprintf(outfile, "break;\n\n");
    } else {
        fprintf(outfile, "static inline void gen_%s(", name);
        if (nb_args == 0) {
            fprintf(outfile, "void");
        } else {
            for(i = 0; i < nb_args; i++) {
                if (i != 0)
                    fprintf(outfile, ", ");
                fprintf(outfile, "long param%d", i + 1);
            }
        }
        fprintf(outfile, ")\n");
        fprintf(outfile, "{\n");
        for(i = 0; i < nb_args; i++) {
            fprintf(outfile, "    *gen_opparam_ptr++ = param%d;\n", i + 1);
        }
        fprintf(outfile, "    *gen_opc_ptr++ = INDEX_%s;\n", name);
        fprintf(outfile, "}\n\n");
    }
}

int gen_file(FILE *outfile, int out_type)
{
    int i;
    EXE_SYM *sym;

    if (out_type == OUT_INDEX_OP) {
        fprintf(outfile, "DEF(end, 0, 0)\n");
        fprintf(outfile, "DEF(nop, 0, 0)\n");
        fprintf(outfile, "DEF(nop1, 1, 0)\n");
        fprintf(outfile, "DEF(nop2, 2, 0)\n");
        fprintf(outfile, "DEF(nop3, 3, 0)\n");
        for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
            const char *name;
            name = get_sym_name(sym);
            if (strstart(name, OP_PREFIX, NULL)) {
                gen_code(name, sym->st_value, sym->st_size, outfile, 2);
            }
        }
    } else if (out_type == OUT_GEN_OP) {
        /* generate gen_xxx functions */
        fprintf(outfile, "#include \"dyngen-op.h\"\n");
        for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
            const char *name;
            name = get_sym_name(sym);
            if (strstart(name, OP_PREFIX, NULL)) {
#if defined(CONFIG_FORMAT_ELF) || defined(CONFIG_FORMAT_COFF)
                if (sym->st_shndx != text_shndx)
                    error("invalid section for opcode (0x%x)", sym->st_shndx);
#endif
                gen_code(name, sym->st_value, sym->st_size, outfile, 0);
            }
        }
        
    } else {
        /* generate big code generation switch */

#ifdef HOST_ARM
        /* We need to know the size of all the ops so we can figure out when
           to emit constant pools.  This must be consistent with opc.h.  */
fprintf(outfile,
"static const uint32_t arm_opc_size[] = {\n"
"  0,\n" /* end */
"  0,\n" /* nop */
"  0,\n" /* nop1 */
"  0,\n" /* nop2 */
"  0,\n"); /* nop3 */
        for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
            const char *name;
            name = get_sym_name(sym);
            if (strstart(name, OP_PREFIX, NULL)) {
                fprintf(outfile, "  %d,\n", sym->st_size);
            }
        }
fprintf(outfile,
"};\n");
#endif

fprintf(outfile,
"int dyngen_code(uint8_t *gen_code_buf,\n"
"                uint16_t *label_offsets, uint16_t *jmp_offsets,\n"
"                const uint16_t *opc_buf, const uint32_t *opparam_buf, const long *gen_labels)\n"
"{\n"
"    uint8_t *gen_code_ptr;\n"
"    const uint16_t *opc_ptr;\n"
"    const uint32_t *opparam_ptr;\n");

#ifdef HOST_ARM
/* Arm is tricky because it uses constant pools for loading immediate values.
   We assume (and require) each function is code followed by a constant pool.
   All the ops are small so this should be ok.  For each op we figure
   out how much "spare" range we have in the load instructions.  This allows
   us to insert subsequent ops in between the op and the constant pool,
   eliminating the neeed to jump around the pool.

   We currently generate:
   
   [ For this example we assume merging would move op1_pool out of range.
     In practice we should be able to combine many ops before the offset
     limits are reached. ]
   op1_code;
   op2_code;
   goto op3;
   op2_pool;
   op1_pool;
op3:
   op3_code;
   ret;
   op3_pool;

   Ideally we'd put op1_pool before op2_pool, but that requires two passes.
 */
fprintf(outfile,
"    uint8_t *last_gen_code_ptr = gen_code_buf;\n"
"    LDREntry *arm_ldr_ptr = arm_ldr_table;\n"
"    uint32_t *arm_data_ptr = arm_data_table + ARM_LDR_TABLE_SIZE;\n"
/* Initialise the parmissible pool offset to an arbitary large value.  */
"    uint8_t *arm_pool_ptr = gen_code_buf + 0x1000000;\n");
#endif
#ifdef HOST_IA64
    {
        long addend, not_first = 0;
        unsigned long sym_idx;
        int index, max_index;
        const char *sym_name;
        EXE_RELOC *rel;

        max_index = -1;
        for (i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
            sym_idx = ELF64_R_SYM(rel->r_info);
            sym_name = (strtab + symtab[sym_idx].st_name);
            if (strstart(sym_name, "__op_gen_label", NULL))
                continue;
            if (ELF64_R_TYPE(rel->r_info) != R_IA64_PCREL21B)
                continue;

            addend = rel->r_addend;
            index = get_plt_index(sym_name, addend);
            if (index <= max_index)
                continue;
            max_index = index;
            fprintf(outfile, "    extern void %s(void);\n", sym_name);
        }

        fprintf(outfile,
                "    struct ia64_fixup *plt_fixes = NULL, "
                "*ltoff_fixes = NULL;\n"
                "    static long plt_target[] = {\n\t");

        max_index = -1;
        for (i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
            sym_idx = ELF64_R_SYM(rel->r_info);
            sym_name = (strtab + symtab[sym_idx].st_name);
            if (strstart(sym_name, "__op_gen_label", NULL))
                continue;
            if (ELF64_R_TYPE(rel->r_info) != R_IA64_PCREL21B)
                continue;

            addend = rel->r_addend;
            index = get_plt_index(sym_name, addend);
            if (index <= max_index)
                continue;
            max_index = index;

            if (not_first)
                fprintf(outfile, ",\n\t");
            not_first = 1;
            if (addend)
                fprintf(outfile, "(long) &%s + %ld", sym_name, addend);
            else
                fprintf(outfile, "(long) &%s", sym_name);
        }
        fprintf(outfile, "\n    };\n"
            "    unsigned int plt_offset[%u] = { 0 };\n", max_index + 1);
    }
#endif

fprintf(outfile,
"\n"
"    gen_code_ptr = gen_code_buf;\n"
"    opc_ptr = opc_buf;\n"
"    opparam_ptr = opparam_buf;\n");

        /* Generate prologue, if needed. */ 

fprintf(outfile,
"    for(;;) {\n");

#ifdef HOST_ARM
/* Generate constant pool if needed */
fprintf(outfile,
"            if (gen_code_ptr + arm_opc_size[*opc_ptr] >= arm_pool_ptr) {\n"
"                gen_code_ptr = arm_flush_ldr(gen_code_ptr, arm_ldr_table, "
"arm_ldr_ptr, arm_data_ptr, arm_data_table + ARM_LDR_TABLE_SIZE, 1);\n"
"                last_gen_code_ptr = gen_code_ptr;\n"
"                arm_ldr_ptr = arm_ldr_table;\n"
"                arm_data_ptr = arm_data_table + ARM_LDR_TABLE_SIZE;\n"
"                arm_pool_ptr = gen_code_ptr + 0x1000000;\n"
"            }\n");
#endif

fprintf(outfile,
"        switch(*opc_ptr++) {\n");

        for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
            const char *name;
            name = get_sym_name(sym);
            if (strstart(name, OP_PREFIX, NULL)) {
#if 0
                printf("%4d: %s pos=0x%08x len=%d\n", 
                       i, name, sym->st_value, sym->st_size);
#endif
#if defined(CONFIG_FORMAT_ELF) || defined(CONFIG_FORMAT_COFF)
                if (sym->st_shndx != text_shndx)
                    error("invalid section for opcode (0x%x)", sym->st_shndx);
#endif
                gen_code(name, sym->st_value, sym->st_size, outfile, 1);
            }
        }

fprintf(outfile,
"        case INDEX_op_nop:\n"
"            break;\n"
"        case INDEX_op_nop1:\n"
"            opparam_ptr++;\n"
"            break;\n"
"        case INDEX_op_nop2:\n"
"            opparam_ptr += 2;\n"
"            break;\n"
"        case INDEX_op_nop3:\n"
"            opparam_ptr += 3;\n"
"            break;\n"
"        default:\n"
"            goto the_end;\n"
"        }\n");


fprintf(outfile,
"    }\n"
" the_end:\n"
);
#ifdef HOST_IA64
    fprintf(outfile,
            "    {\n"
            "      extern char code_gen_buffer[];\n"
            "      ia64_apply_fixes(&gen_code_ptr, ltoff_fixes, "
            "(uint64_t) code_gen_buffer + 2*(1<<20), plt_fixes,\n\t\t\t"
            "sizeof(plt_target)/sizeof(plt_target[0]),\n\t\t\t"
            "plt_target, plt_offset);\n    }\n");
#endif

/* generate some code patching */ 
#ifdef HOST_ARM
fprintf(outfile,
"if (arm_data_ptr != arm_data_table + ARM_LDR_TABLE_SIZE)\n"
"    gen_code_ptr = arm_flush_ldr(gen_code_ptr, arm_ldr_table, "
"arm_ldr_ptr, arm_data_ptr, arm_data_table + ARM_LDR_TABLE_SIZE, 0);\n");
#endif
    /* flush instruction cache */
    fprintf(outfile, "flush_icache_range((unsigned long)gen_code_buf, (unsigned long)gen_code_ptr);\n");

    fprintf(outfile, "return gen_code_ptr -  gen_code_buf;\n");
    fprintf(outfile, "}\n\n");

    }

    return 0;
}

void usage(void)
{
    printf("dyngen (c) 2003 Fabrice Bellard\n"
           "usage: dyngen [-o outfile] [-c] objfile\n"
           "Generate a dynamic code generator from an object file\n"
           "-c     output enum of operations\n"
           "-g     output gen_op_xx() functions\n"
           );
    exit(1);
}

int main(int argc, char **argv)
{
    int c, out_type;
    const char *filename, *outfilename;
    FILE *outfile;

    outfilename = "out.c";
    out_type = OUT_CODE;
    for(;;) {
        c = getopt(argc, argv, "ho:cg");
        if (c == -1)
            break;
        switch(c) {
        case 'h':
            usage();
            break;
        case 'o':
            outfilename = optarg;
            break;
        case 'c':
            out_type = OUT_INDEX_OP;
            break;
        case 'g':
            out_type = OUT_GEN_OP;
            break;
        }
    }
    if (optind >= argc)
        usage();
    filename = argv[optind];
    outfile = fopen(outfilename, "w");
    if (!outfile)
        error("could not open '%s'", outfilename);

    load_object(filename);
    gen_file(outfile, out_type);
    fclose(outfile);
    return 0;
}

/* bird added: */
/*
 * Local Variables:
 *  mode: c
 *  c-file-style: k&r
 *  c-basic-offset: 4
 *  tab-width: 4
 *  indent-tabs-mode: t
 * End:
 */