#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <libmcpu.h>
#include <mcpu-elf.h>

#include "mcpu-melf.h"
#include "mcpu-version.h"


typedef struct __readelf_shdr
{
  __mpu_uint32_t  name;
  __mpu_uint32_t  type;
  __mpu_uint64_t  flags;
  __mpu_uint64_t  addr;
  __mpu_uint64_t  offset;
  __mpu_uint64_t  size;
  __mpu_uint32_t  link;
  __mpu_uint32_t  info;
  __mpu_uint64_t  align;
  __mpu_uint64_t  entsize;
} readelf_shdr;


typedef struct __readelf_phdr
{
  __mpu_uint32_t  type;
  __mpu_uint32_t  flags;
  __mpu_uint64_t  offset;
  __mpu_uint64_t  vaddr;
  __mpu_uint64_t  paddr;
  __mpu_uint64_t  filesz;
  __mpu_uint64_t  memsz;
  __mpu_uint64_t  maxsz;
  __mpu_uint64_t  align;
} readelf_phdr;


typedef struct __readelf_file
{
  const char          *path;
  unsigned char       *file;
  size_t               file_size;
  int                  data;

  __mpu_uint16_t       type;
  __mpu_uint16_t       machine;
  __mpu_uint32_t       version;
  __mpu_uint64_t       entry;
  __mpu_uint64_t       init_entry;
  __mpu_uint64_t       life_entry;
  __mpu_uint64_t       fini_entry;
  __mpu_uint64_t       phoff;
  __mpu_uint64_t       shoff;
  __mpu_uint32_t       flags;
  __mpu_uint16_t       ehsize;
  __mpu_uint16_t       phentsize;
  __mpu_uint16_t       phnum;
  __mpu_uint16_t       shentsize;
  __mpu_uint16_t       shnum;
  __mpu_uint16_t       shstrndx;

  readelf_phdr        *phdr;
  readelf_shdr        *shdr;
  const unsigned char *shstr;
  size_t               shstr_size;
} readelf_file;


typedef struct __readelf_options
{
  int file_header;
  int program_headers;
  int section_headers;
  int symbols;
  int relocations;
  int dynamic;
  int arch_specific;
  int wide;
} readelf_options;


static void
usage( FILE *fp, const char *name )
{
  fprintf( fp,
    "usage: %s <option(s)> MELF-file(s)\n\n"
    "Display information about LibMCPU MELF ABI1/ABI2/ABI3 files.\n\n"
    "Options:\n"
    "  -a, --all                 - equivalent to -h -l -S -s -r -d -A\n"
    "  -e, --headers             - equivalent to -h -l -S\n"
    "  -h, --file-header         - display the MELF file header\n"
    "  -l, --program-headers     - display the program headers\n"
    "      --segments            - alias for --program-headers\n"
    "  -S, --section-headers     - display the section headers\n"
    "      --sections            - alias for --section-headers\n"
    "  -s, --symbols             - display symbol tables (.symtab/.dynsym)\n"
    "      --syms                - alias for --symbols\n"
    "  -r, --relocs              - display RELA relocation sections\n"
    "  -d, --dynamic             - display ABI-v3 dynamic dependency metadata\n"
    "  -A, --arch-specific       - display MCPU target/lifecycle metadata\n"
    "  -W, --wide                - do not truncate output (accepted for compatibility)\n"
    "      --help                - show this help\n"
    "      --version             - show program version\n"
    "      --dump-version        - show version number only\n",
    name );

} /* End of usage() */


static const char *
file_type_name( unsigned int type )
{
  switch( type )
  {
    case MELF_ET_NONE: return( "NONE (None)" );
    case MELF_ET_REL:  return( "REL (Relocatable file)" );
    case MELF_ET_EXEC: return( "EXEC (Executable file)" );
    case MELF_ET_DYN:  return( "DYN (Shared object file)" );
    case MELF_ET_CORE: return( "CORE (Core file)" );
    default:           return( "<unknown>" );
  }

} /* End of file_type_name() */


static const char *
section_type_name( __mpu_uint32_t type )
{
  switch( type )
  {
    case MELF_SHT_NULL:           return( "NULL" );
    case MELF_SHT_PROGBITS:       return( "PROGBITS" );
    case MELF_SHT_SYMTAB:         return( "SYMTAB" );
    case MELF_SHT_STRTAB:         return( "STRTAB" );
    case MELF_SHT_RELA:           return( "RELA" );
    case MELF_SHT_DYNAMIC:        return( "DYNAMIC" );
    case MELF_SHT_NOBITS:         return( "NOBITS" );
    case MELF_SHT_DYNSYM:         return( "DYNSYM" );
    case MELF_SHT_MCPU_TARGET:    return( "MCPU_TARGET" );
    case MELF_SHT_MCPU_LIFECYCLE: return( "MCPU_LIFECYCLE" );
    default:                       return( "<unknown>" );
  }

} /* End of section_type_name() */


static const char *
program_type_name( __mpu_uint32_t type )
{
  switch( type )
  {
    case MELF_PT_NULL:       return( "NULL" );
    case MELF_PT_LOAD:       return( "LOAD" );
    case MELF_PT_MCPU_STACK: return( "MCPU_STACK" );
    case MELF_PT_MCPU_HEAP:  return( "MCPU_HEAP" );
    default:                  return( "<unknown>" );
  }

} /* End of program_type_name() */


static const char *
symbol_bind_name( unsigned int bind )
{
  switch( bind )
  {
    case MELF_STB_LOCAL:  return( "LOCAL" );
    case MELF_STB_GLOBAL: return( "GLOBAL" );
    case MELF_STB_WEAK:   return( "WEAK" );
    default:               return( "<unknown>" );
  }

} /* End of symbol_bind_name() */


static const char *
symbol_type_name( unsigned int type )
{
  switch( type )
  {
    case MELF_STT_NOTYPE:  return( "NOTYPE" );
    case MELF_STT_OBJECT:  return( "OBJECT" );
    case MELF_STT_FUNC:    return( "FUNC" );
    case MELF_STT_SECTION: return( "SECTION" );
    case MELF_STT_FILE:    return( "FILE" );
    default:                return( "<unknown>" );
  }

} /* End of symbol_type_name() */


static const char *
symbol_visibility_name( unsigned int visibility )
{
  switch( visibility )
  {
    case MELF_STV_DEFAULT:   return( "DEFAULT" );
    case MELF_STV_INTERNAL:  return( "INTERNAL" );
    case MELF_STV_HIDDEN:    return( "HIDDEN" );
    case MELF_STV_PROTECTED: return( "PROTECTED" );
    default:                  return( "<unknown>" );
  }

} /* End of symbol_visibility_name() */


static const char *
relocation_type_name( __mpu_uint32_t type )
{
  switch( type )
  {
    case MELF_R_MCPU_NONE:        return( "R_MCPU_NONE" );
    case MELF_R_MCPU_CODE64:      return( "R_MCPU_CODE64" );
    case MELF_R_MCPU_DATA64:      return( "R_MCPU_DATA64" );
    case MELF_R_MCPU_PTR64_CODE:  return( "R_MCPU_PTR64_CODE" );
    case MELF_R_MCPU_PTR64_DATA:  return( "R_MCPU_PTR64_DATA" );
    case MELF_R_MCPU_CPTR64_DATA: return( "R_MCPU_CPTR64_DATA" );
    default:                       return( "<unknown>" );
  }

} /* End of relocation_type_name() */


static void
get_shdr( const unsigned char *p, int data, readelf_shdr *sh )
{
  memset( sh, 0, sizeof( *sh ) );
  sh->name = cpu_melf_get32( p + MELF64_SHDR_SH_NAME_OFF, data );
  sh->type = cpu_melf_get32( p + MELF64_SHDR_SH_TYPE_OFF, data );
  sh->flags = cpu_melf_get64( p + MELF64_SHDR_SH_FLAGS_OFF, data );
  sh->addr = cpu_melf_get64( p + MELF64_SHDR_SH_ADDR_OFF, data );
  sh->offset = cpu_melf_get64( p + MELF64_SHDR_SH_OFFSET_OFF, data );
  sh->size = cpu_melf_get64( p + MELF64_SHDR_SH_SIZE_OFF, data );
  sh->link = cpu_melf_get32( p + MELF64_SHDR_SH_LINK_OFF, data );
  sh->info = cpu_melf_get32( p + MELF64_SHDR_SH_INFO_OFF, data );
  sh->align = cpu_melf_get64( p + MELF64_SHDR_SH_ADDRALIGN_OFF, data );
  sh->entsize = cpu_melf_get64( p + MELF64_SHDR_SH_ENTSIZE_OFF, data );

} /* End of get_shdr() */


static void
get_phdr( const unsigned char *p, int data, readelf_phdr *ph )
{
  memset( ph, 0, sizeof( *ph ) );
  ph->type = cpu_melf_get32( p + MELF64_PHDR_P_TYPE_OFF, data );
  ph->flags = cpu_melf_get32( p + MELF64_PHDR_P_FLAGS_OFF, data );
  ph->offset = cpu_melf_get64( p + MELF64_PHDR_P_OFFSET_OFF, data );
  ph->vaddr = cpu_melf_get64( p + MELF64_PHDR_P_VADDR_OFF, data );
  ph->paddr = cpu_melf_get64( p + MELF64_PHDR_P_PADDR_OFF, data );
  ph->filesz = cpu_melf_get64( p + MELF64_PHDR_P_FILESZ_OFF, data );
  ph->memsz = cpu_melf_get64( p + MELF64_PHDR_P_MEMSZ_OFF, data );
  ph->maxsz = cpu_melf_get64( p + MELF64_PHDR_P_MAXSZ_OFF, data );
  ph->align = cpu_melf_get64( p + MELF64_PHDR_P_ALIGN_OFF, data );

} /* End of get_phdr() */


static void
readelf_file_free( readelf_file *m )
{
  if( !m )
    return;

  free( m->phdr );
  free( m->shdr );
  free( m->file );
  memset( m, 0, sizeof( *m ) );

} /* End of readelf_file_free() */


static int
readelf_file_open( const char *path, readelf_file *m, char *err, size_t errsz )
{
  const unsigned char *h;
  size_t               i;

  memset( m, 0, sizeof( *m ) );
  m->path = path;

  if( cpu_melf_readall( path, &m->file, &m->file_size, err, errsz ) )
    return( -1 );

  if( m->file_size < MELF64_EHDR_SIZE )
  {
    snprintf( err, errsz, "%s: file is too small for a MELF64 header", path );
    goto fail;
  }

  h = m->file;
  if( h[MELF_EI_MAG0] != MELFMAG0 || h[MELF_EI_MAG1] != MELFMAG1 ||
      h[MELF_EI_MAG2] != MELFMAG2 || h[MELF_EI_MAG3] != MELFMAG3 )
  {
    snprintf( err, errsz, "%s: not a MELF file", path );
    goto fail;
  }

  if( h[MELF_EI_CLASS] != MELF_CLASS_64 )
  {
    snprintf( err, errsz, "%s: unsupported MELF class %u", path,
              (unsigned int)h[MELF_EI_CLASS] );
    goto fail;
  }

  m->data = h[MELF_EI_DATA];
  if( m->data != MELF_DATA_LSB && m->data != MELF_DATA_MSB )
  {
    snprintf( err, errsz, "%s: invalid MELF data encoding %d", path, m->data );
    goto fail;
  }

  m->type = cpu_melf_get16( h + MELF64_EHDR_E_TYPE_OFF, m->data );
  m->machine = cpu_melf_get16( h + MELF64_EHDR_E_MACHINE_OFF, m->data );
  m->version = cpu_melf_get32( h + MELF64_EHDR_E_VERSION_OFF, m->data );
  m->entry = cpu_melf_get64( h + MELF64_EHDR_E_ENTRY_OFF, m->data );
  m->init_entry = cpu_melf_get64( h + MELF64_EHDR_E_INIT_ENTRY_OFF, m->data );
  m->life_entry = cpu_melf_get64( h + MELF64_EHDR_E_LIFE_ENTRY_OFF, m->data );
  m->fini_entry = cpu_melf_get64( h + MELF64_EHDR_E_FINI_ENTRY_OFF, m->data );
  m->phoff = cpu_melf_get64( h + MELF64_EHDR_E_PHOFF_OFF, m->data );
  m->shoff = cpu_melf_get64( h + MELF64_EHDR_E_SHOFF_OFF, m->data );
  m->flags = cpu_melf_get32( h + MELF64_EHDR_E_FLAGS_OFF, m->data );
  m->ehsize = cpu_melf_get16( h + MELF64_EHDR_E_EHSIZE_OFF, m->data );
  m->phentsize = cpu_melf_get16( h + MELF64_EHDR_E_PHENTSIZE_OFF, m->data );
  m->phnum = cpu_melf_get16( h + MELF64_EHDR_E_PHNUM_OFF, m->data );
  m->shentsize = cpu_melf_get16( h + MELF64_EHDR_E_SHENTSIZE_OFF, m->data );
  m->shnum = cpu_melf_get16( h + MELF64_EHDR_E_SHNUM_OFF, m->data );
  m->shstrndx = cpu_melf_get16( h + MELF64_EHDR_E_SHSTRNDX_OFF, m->data );

  if( m->ehsize != MELF64_EHDR_SIZE )
  {
    snprintf( err, errsz, "%s: unsupported MELF64 header size %u", path,
              (unsigned int)m->ehsize );
    goto fail;
  }

  if( m->phnum )
  {
    if( m->phentsize != MELF64_PHDR_SIZE ||
        !cpu_melf_span( m->file_size, m->phoff,
                        (__mpu_uint64_t)m->phnum * MELF64_PHDR_SIZE ) )
    {
      snprintf( err, errsz, "%s: malformed program-header table", path );
      goto fail;
    }

    m->phdr = (readelf_phdr *)calloc( m->phnum, sizeof( *m->phdr ) );
    if( !m->phdr )
    {
      snprintf( err, errsz, "out of memory" );
      goto fail;
    }

    for( i = 0; i < m->phnum; ++i )
      get_phdr( m->file + (size_t)m->phoff + i * MELF64_PHDR_SIZE,
                m->data, &m->phdr[i] );
  }
  else if( m->phentsize != 0 && m->phentsize != MELF64_PHDR_SIZE )
  {
    snprintf( err, errsz, "%s: unsupported program-header entry size %u", path,
              (unsigned int)m->phentsize );
    goto fail;
  }

  if( m->shnum )
  {
    if( m->shentsize != MELF64_SHDR_SIZE ||
        !cpu_melf_span( m->file_size, m->shoff,
                        (__mpu_uint64_t)m->shnum * MELF64_SHDR_SIZE ) )
    {
      snprintf( err, errsz, "%s: malformed section-header table", path );
      goto fail;
    }

    m->shdr = (readelf_shdr *)calloc( m->shnum, sizeof( *m->shdr ) );
    if( !m->shdr )
    {
      snprintf( err, errsz, "out of memory" );
      goto fail;
    }

    for( i = 0; i < m->shnum; ++i )
      get_shdr( m->file + (size_t)m->shoff + i * MELF64_SHDR_SIZE,
                m->data, &m->shdr[i] );

    if( m->shstrndx >= m->shnum ||
        m->shdr[m->shstrndx].type != MELF_SHT_STRTAB ||
        !cpu_melf_span( m->file_size, m->shdr[m->shstrndx].offset,
                        m->shdr[m->shstrndx].size ) )
    {
      snprintf( err, errsz, "%s: malformed section-name string table", path );
      goto fail;
    }

    m->shstr = m->file + (size_t)m->shdr[m->shstrndx].offset;
    m->shstr_size = (size_t)m->shdr[m->shstrndx].size;
  }
  else if( m->shentsize != 0 && m->shentsize != MELF64_SHDR_SIZE )
  {
    snprintf( err, errsz, "%s: unsupported section-header entry size %u", path,
              (unsigned int)m->shentsize );
    goto fail;
  }

  return( 0 );

fail:
  readelf_file_free( m );
  return( -1 );

} /* End of readelf_file_open() */


static const char *
string_at( const unsigned char *table, size_t size, __mpu_uint64_t offset )
{
  const unsigned char *p;

  if( !table || offset >= size )
    return( "<corrupt>" );

  p = table + (size_t)offset;
  if( !memchr( p, '\0', size - (size_t)offset ) )
    return( "<corrupt>" );

  return( (const char *)p );

} /* End of string_at() */


static const char *
section_name( const readelf_file *m, size_t index )
{
  if( !m->shdr || index >= m->shnum )
    return( "<invalid>" );

  return( string_at( m->shstr, m->shstr_size, m->shdr[index].name ) );

} /* End of section_name() */


static int
section_payload( const readelf_file *m, size_t index,
                 const unsigned char **payload, size_t *size )
{
  const readelf_shdr *sh;

  if( !m->shdr || index >= m->shnum )
    return( -1 );

  sh = &m->shdr[index];
  if( sh->type == MELF_SHT_NOBITS )
  {
    *payload = NULL;
    *size = (size_t)sh->size;
    return( 0 );
  }

  if( sh->size > SIZE_MAX ||
      !cpu_melf_span( m->file_size, sh->offset, sh->size ) )
    return( -1 );

  *payload = m->file + (size_t)sh->offset;
  *size = (size_t)sh->size;
  return( 0 );

} /* End of section_payload() */


static void
print_file_header( const readelf_file *m )
{
  const unsigned char *h = m->file;
  size_t               i;

  printf( "MELF Header:\n" );
  printf( "  Magic:  " );
  for( i = 0; i < MELF_EI_NIDENT; ++i )
    printf( " %02x", (unsigned int)h[i] );
  printf( "\n" );
  printf( "  Class:                             MELF64\n" );
  printf( "  Data:                              %s endian\n",
          m->data == MELF_DATA_LSB ? "little" : "big" );
  printf( "  Version:                           %u\n",
          (unsigned int)h[MELF_EI_VERSION] );
  printf( "  OS/ABI:                            %s\n",
          h[MELF_EI_OSABI] == MELF_OSABI_MCPU ? "MCPU" : "<unknown>" );
  printf( "  ABI Version:                       %u\n",
          (unsigned int)h[MELF_EI_ABIVERSION] );
  printf( "  Type:                              %s\n", file_type_name( m->type ) );
  printf( "  Machine:                           %s (0x%04x)\n",
          m->machine == MELF_EM_MCPU ? "MCPU" : "<unknown>",
          (unsigned int)m->machine );
  printf( "  Version:                           0x%x\n", (unsigned int)m->version );
  printf( "  Entry point address:               0x%016" PRIx64 "\n",
          (uint64_t)m->entry );
  printf( "  INIT entry address:                0x%016" PRIx64 "\n",
          (uint64_t)m->init_entry );
  printf( "  LIFE entry address:                0x%016" PRIx64 "\n",
          (uint64_t)m->life_entry );
  printf( "  FINI entry address:                0x%016" PRIx64 "\n",
          (uint64_t)m->fini_entry );
  printf( "  Start of program headers:          %" PRIu64 " (bytes into file)\n",
          (uint64_t)m->phoff );
  printf( "  Start of section headers:          %" PRIu64 " (bytes into file)\n",
          (uint64_t)m->shoff );
  printf( "  Flags:                             0x%x\n", (unsigned int)m->flags );
  printf( "  Size of this header:               %u (bytes)\n",
          (unsigned int)m->ehsize );
  printf( "  Size of program headers:           %u (bytes)\n",
          (unsigned int)m->phentsize );
  printf( "  Number of program headers:         %u\n", (unsigned int)m->phnum );
  printf( "  Size of section headers:           %u (bytes)\n",
          (unsigned int)m->shentsize );
  printf( "  Number of section headers:         %u\n", (unsigned int)m->shnum );
  printf( "  Section header string table index: %u\n", (unsigned int)m->shstrndx );

} /* End of print_file_header() */


static void
print_program_headers( const readelf_file *m )
{
  size_t i;

  if( !m->phnum )
  {
    printf( "There are no program headers in this file.\n" );
    return;
  }

  printf( "There are %u program headers, starting at offset %" PRIu64 ":\n\n",
          (unsigned int)m->phnum, (uint64_t)m->phoff );
  printf( "Program Headers:\n" );
  printf( "  Type          Offset             VirtAddr           PhysAddr\n" );
  printf( "                FileSiz            MemSiz             MaxSiz              Flg Align\n" );

  for( i = 0; i < m->phnum; ++i )
  {
    const readelf_phdr *ph = &m->phdr[i];
    char flags[4];

    flags[0] = (ph->flags & MELF_PF_R) ? 'R' : ' ';
    flags[1] = (ph->flags & MELF_PF_W) ? 'W' : ' ';
    flags[2] = (ph->flags & MELF_PF_X) ? 'E' : ' ';
    flags[3] = '\0';

    printf( "  %-13s 0x%016" PRIx64 " 0x%016" PRIx64 " 0x%016" PRIx64 "\n",
            program_type_name( ph->type ), (uint64_t)ph->offset,
            (uint64_t)ph->vaddr, (uint64_t)ph->paddr );
    printf( "                0x%016" PRIx64 " 0x%016" PRIx64 " 0x%016" PRIx64
            " %3s 0x%" PRIx64 "\n",
            (uint64_t)ph->filesz, (uint64_t)ph->memsz, (uint64_t)ph->maxsz,
            flags, (uint64_t)ph->align );
  }

} /* End of print_program_headers() */


static void
section_flags( __mpu_uint64_t flags, char out[8] )
{
  size_t n = 0;

  if( flags & MELF_SHF_WRITE )
    out[n++] = 'W';
  if( flags & MELF_SHF_ALLOC )
    out[n++] = 'A';
  if( flags & MELF_SHF_EXECINSTR )
    out[n++] = 'X';
  if( MELF_SHF_MCPU_HAS_SEG( flags ) )
  {
    unsigned int seg = MELF_SHF_MCPU_GET_SEG( flags );

    if( seg <= MELF_MCPU_SEG_HEAP )
    {
      switch( seg )
      {
        case MELF_MCPU_SEG_DATA:    out[n++] = 'D'; break;
        case MELF_MCPU_SEG_STACK:   out[n++] = 'S'; break;
        case MELF_MCPU_SEG_PROGRAM: out[n++] = 'P'; break;
        case MELF_MCPU_SEG_CONTROL: out[n++] = 'C'; break;
        case MELF_MCPU_SEG_INPUT:   out[n++] = 'I'; break;
        case MELF_MCPU_SEG_OUTPUT:  out[n++] = 'O'; break;
        case MELF_MCPU_SEG_TRACE:   out[n++] = 'T'; break;
        case MELF_MCPU_SEG_HEAP:    out[n++] = 'H'; break;
      }
    }
  }
  out[n] = '\0';

} /* End of section_flags() */


static void
print_section_headers( const readelf_file *m )
{
  size_t i;

  if( !m->shnum )
  {
    printf( "There are no section headers in this file.\n" );
    return;
  }

  printf( "There are %u section headers, starting at offset 0x%" PRIx64 ":\n\n",
          (unsigned int)m->shnum, (uint64_t)m->shoff );
  printf( "Section Headers:\n" );
  printf( "  [Nr] Name                 Type             Address            Offset   "
          "Size               EntSize            Flags Link Info Align\n" );

  for( i = 0; i < m->shnum; ++i )
  {
    const readelf_shdr *sh = &m->shdr[i];
    char                 flags[8];

    section_flags( sh->flags, flags );
    printf( "  [%2zu] %-20s %-16s %016" PRIx64 " %08" PRIx64
            " %016" PRIx64 " %016" PRIx64 " %-5s %4u %4u %5" PRIu64 "\n",
            i, section_name( m, i ), section_type_name( sh->type ),
            (uint64_t)sh->addr, (uint64_t)sh->offset,
            (uint64_t)sh->size, (uint64_t)sh->entsize, flags,
            (unsigned int)sh->link, (unsigned int)sh->info,
            (uint64_t)sh->align );
  }

  printf( "Key to Flags: W (write), A (alloc), X (execute), "
          "D/S/P/C/I/O/T/H (MCPU segment)\n" );

} /* End of print_section_headers() */


static int
get_symbol( const readelf_file *m, size_t table_index, size_t symbol_index,
            __mpu_uint32_t *name, unsigned int *bind, unsigned int *type,
            unsigned int *visibility, __mpu_uint16_t *shndx,
            __mpu_uint64_t *value, __mpu_uint64_t *size )
{
  const readelf_shdr    *sh;
  const unsigned char   *p;
  __mpu_uint8_t          info;
  __mpu_uint8_t          other;
  __mpu_uint64_t         count;

  if( table_index >= m->shnum )
    return( -1 );
  sh = &m->shdr[table_index];
  if( sh->type != MELF_SHT_SYMTAB && sh->type != MELF_SHT_DYNSYM )
    return( -1 );
  if( sh->entsize != MELF64_SYM_SIZE || sh->size % MELF64_SYM_SIZE )
    return( -1 );
  count = sh->size / MELF64_SYM_SIZE;
  if( symbol_index >= count ||
      !cpu_melf_span( m->file_size, sh->offset, sh->size ) )
    return( -1 );

  p = m->file + (size_t)sh->offset + symbol_index * MELF64_SYM_SIZE;
  *name = cpu_melf_get32( p + MELF64_SYM_ST_NAME_OFF, m->data );
  info = p[MELF64_SYM_ST_INFO_OFF];
  other = p[MELF64_SYM_ST_OTHER_OFF];
  *bind = MELF64_ST_BIND( info );
  *type = MELF64_ST_TYPE( info );
  *visibility = MELF_ST_VISIBILITY( other );
  *shndx = cpu_melf_get16( p + MELF64_SYM_ST_SHNDX_OFF, m->data );
  *value = cpu_melf_get64( p + MELF64_SYM_ST_VALUE_OFF, m->data );
  *size = cpu_melf_get64( p + MELF64_SYM_ST_SIZE_OFF, m->data );
  return( 0 );

} /* End of get_symbol() */


static const char *
symbol_name( const readelf_file *m, size_t table_index, __mpu_uint32_t name )
{
  const readelf_shdr  *sh;
  const readelf_shdr  *str;
  const unsigned char *payload;
  size_t               payload_size;

  if( table_index >= m->shnum )
    return( "<invalid>" );
  sh = &m->shdr[table_index];
  if( sh->link >= m->shnum )
    return( "<invalid>" );
  str = &m->shdr[sh->link];
  if( str->type != MELF_SHT_STRTAB ||
      section_payload( m, sh->link, &payload, &payload_size ) )
    return( "<invalid>" );

  return( string_at( payload, payload_size, name ) );

} /* End of symbol_name() */


static void
print_symbol_index( __mpu_uint16_t shndx )
{
  if( shndx == MELF_SHN_UNDEF )
    printf( "%4s", "UND" );
  else if( shndx == MELF_SHN_ABS )
    printf( "%4s", "ABS" );
  else if( shndx == MELF_SHN_COMMON )
    printf( "%4s", "COM" );
  else
    printf( "%4u", (unsigned int)shndx );

} /* End of print_symbol_index() */


static void
print_symbols( const readelf_file *m )
{
  size_t i;

  for( i = 0; i < m->shnum; ++i )
  {
    const readelf_shdr *sh = &m->shdr[i];
    __mpu_uint64_t      count;
    size_t              j;

    if( sh->type != MELF_SHT_SYMTAB && sh->type != MELF_SHT_DYNSYM )
      continue;

    if( sh->entsize != MELF64_SYM_SIZE || sh->size % MELF64_SYM_SIZE ||
        !cpu_melf_span( m->file_size, sh->offset, sh->size ) )
    {
      printf( "Symbol table '%s' is malformed.\n", section_name( m, i ) );
      continue;
    }

    count = sh->size / MELF64_SYM_SIZE;
    printf( "Symbol table '%s' contains %" PRIu64 " entries:\n",
            section_name( m, i ), (uint64_t)count );
    printf( "   Num:    Value          Size Type     Bind     Vis       Ndx Name\n" );

    for( j = 0; j < count; ++j )
    {
      __mpu_uint32_t name;
      unsigned int   bind;
      unsigned int   type;
      unsigned int   visibility;
      __mpu_uint16_t shndx;
      __mpu_uint64_t value;
      __mpu_uint64_t size;

      if( get_symbol( m, i, j, &name, &bind, &type, &visibility, &shndx,
                      &value, &size ) )
        break;

      printf( "%6zu: %016" PRIx64 " %5" PRIu64 " %-8s %-8s %-9s ",
              j, (uint64_t)value, (uint64_t)size,
              symbol_type_name( type ), symbol_bind_name( bind ),
              symbol_visibility_name( visibility ) );
      print_symbol_index( shndx );
      printf( " %s\n", symbol_name( m, i, name ) );
    }
    printf( "\n" );
  }

} /* End of print_symbols() */


static void
print_relocations( const readelf_file *m )
{
  size_t i;

  for( i = 0; i < m->shnum; ++i )
  {
    const readelf_shdr *sh = &m->shdr[i];
    __mpu_uint64_t      count;
    size_t              j;

    if( sh->type != MELF_SHT_RELA )
      continue;

    if( sh->entsize != MELF64_RELA_SIZE || sh->size % MELF64_RELA_SIZE ||
        !cpu_melf_span( m->file_size, sh->offset, sh->size ) ||
        sh->link >= m->shnum ||
        (m->shdr[sh->link].type != MELF_SHT_SYMTAB &&
         m->shdr[sh->link].type != MELF_SHT_DYNSYM) )
    {
      printf( "Relocation section '%s' is malformed.\n", section_name( m, i ) );
      continue;
    }

    count = sh->size / MELF64_RELA_SIZE;
    printf( "Relocation section '%s' at offset 0x%" PRIx64
            " contains %" PRIu64 " entries:\n",
            section_name( m, i ), (uint64_t)sh->offset, (uint64_t)count );
    printf( "  Offset             Info               Type                 Sym.Value          Sym.Name + Addend\n" );

    for( j = 0; j < count; ++j )
    {
      const unsigned char *p;
      __mpu_uint64_t       offset;
      __mpu_uint64_t       info;
      __mpu_int64_t        addend;
      __mpu_uint32_t       sym;
      __mpu_uint32_t       type;
      __mpu_uint32_t       name = 0;
      unsigned int         bind = 0;
      unsigned int         stype = 0;
      unsigned int         visibility = 0;
      __mpu_uint16_t       shndx = 0;
      __mpu_uint64_t       value = 0;
      __mpu_uint64_t       ssize = 0;
      const char          *sname = "<invalid>";

      p = m->file + (size_t)sh->offset + j * MELF64_RELA_SIZE;
      offset = cpu_melf_get64( p + MELF64_RELA_R_OFFSET_OFF, m->data );
      info = cpu_melf_get64( p + MELF64_RELA_R_INFO_OFF, m->data );
      addend = (__mpu_int64_t)cpu_melf_get64( p + MELF64_RELA_R_ADDEND_OFF,
                                              m->data );
      sym = MELF64_R_SYM( info );
      type = MELF64_R_TYPE( info );

      if( !get_symbol( m, sh->link, sym, &name, &bind, &stype, &visibility,
                       &shndx, &value, &ssize ) )
        sname = symbol_name( m, sh->link, name );

      printf( "  %016" PRIx64 " %016" PRIx64 " %-20s %016" PRIx64
              " %s %c 0x%" PRIx64 "\n",
              (uint64_t)offset, (uint64_t)info, relocation_type_name( type ),
              (uint64_t)value, sname, addend < 0 ? '-' : '+',
              (uint64_t)(addend < 0 ? -(__mpu_uint64_t)addend :
                                     (__mpu_uint64_t)addend) );
      (void)bind;
      (void)stype;
      (void)visibility;
      (void)shndx;
      (void)ssize;
    }
    printf( "\n" );
  }

} /* End of print_relocations() */


static const char *
dynamic_tag_name( __mpu_int64_t tag )
{
  switch( tag )
  {
    case MELF_DT_NULL:   return( "NULL" );
    case MELF_DT_NEEDED: return( "NEEDED" );
    case MELF_DT_SONAME: return( "SONAME" );
    default:             return( "<unknown>" );
  }

} /* End of dynamic_tag_name() */


static void
print_dynamic( const readelf_file *m )
{
  size_t i;
  int    printed = 0;

  for( i = 0; i < m->shnum; ++i )
  {
    const readelf_shdr    *sh = &m->shdr[i];
    const readelf_shdr    *str;
    const unsigned char   *payload;
    const unsigned char   *strings;
    size_t                 payload_size;
    size_t                 strings_size;
    size_t                 count;
    size_t                 j;

    if( sh->type != MELF_SHT_DYNAMIC )
      continue;

    printed = 1;
    if( sh->link >= m->shnum ||
        m->shdr[sh->link].type != MELF_SHT_STRTAB ||
        sh->entsize != MELF64_DYN_SIZE ||
        sh->size < MELF64_DYN_SIZE ||
        sh->size % MELF64_DYN_SIZE ||
        section_payload( m, i, &payload, &payload_size ) ||
        section_payload( m, sh->link, &strings, &strings_size ) )
    {
      printf( "Dynamic section '%s' is malformed.\n", section_name( m, i ) );
      continue;
    }

    str = &m->shdr[sh->link];
    (void)str;
    count = payload_size / MELF64_DYN_SIZE;
    printf( "Dynamic section '%s' at offset 0x%" PRIx64
            " contains %zu entries:\n",
            section_name( m, i ), (uint64_t)sh->offset, count );
    printf( "  Tag                Type                 Name/Value\n" );

    for( j = 0; j < count; ++j )
    {
      const unsigned char *dp = payload + j * MELF64_DYN_SIZE;
      __mpu_int64_t tag =
        (__mpu_int64_t)cpu_melf_get64( dp + MELF64_DYN_D_TAG_OFF, m->data );
      __mpu_uint64_t val =
        cpu_melf_get64( dp + MELF64_DYN_D_VAL_OFF, m->data );

      printf( "  0x%016" PRIx64 " %-20s ",
              (uint64_t)tag, dynamic_tag_name( tag ) );
      if( tag == MELF_DT_NEEDED )
        printf( "Shared library: [%s]\n",
                string_at( strings, strings_size, val ) );
      else if( tag == MELF_DT_SONAME )
        printf( "Library soname: [%s]\n",
                string_at( strings, strings_size, val ) );
      else
        printf( "0x%" PRIx64 "\n", (uint64_t)val );
    }
    printf( "\n" );
  }

  if( !printed )
    printf( "There is no dynamic section in this file.\n" );

} /* End of print_dynamic() */


static void
print_target( const MElf_McpuTarget *t )
{
  printf( "MCPU target attributes:\n" );
  printf( "  metadata version:       %u\n", (unsigned int)t->mt_version );
  printf( "  metadata size:          %u\n", (unsigned int)t->mt_size );
  printf( "  ISA revision:           %u\n", (unsigned int)t->mt_isa_revision );
  printf( "  ABI revision:           %u\n", (unsigned int)t->mt_abi_revision );
  printf( "  program model:          %u\n", (unsigned int)t->mt_program_model );
  printf( "  data byte order:        %u\n", (unsigned int)t->mt_data_byte_order );
  printf( "  data word order:        %u\n", (unsigned int)t->mt_data_word_order );
  printf( "  integer model:          %u\n", (unsigned int)t->mt_integer_model );
  printf( "  address model:          %u\n", (unsigned int)t->mt_address_model );
  printf( "  register model:         %u\n", (unsigned int)t->mt_register_model );
  printf( "  real model:             %u\n", (unsigned int)t->mt_real_model );
  printf( "  complex model:          %u\n", (unsigned int)t->mt_complex_model );
  printf( "  maximum ABI alignment:  %u\n", (unsigned int)t->mt_max_align );
  printf( "  flags:                  0x%08x\n", (unsigned int)t->mt_flags );
  printf( "  required features:      0x%016" PRIx64 "\n",
          (uint64_t)t->mt_required_features );

} /* End of print_target() */


static void
print_lifecycle( const MElf_McpuLifecycle *l )
{
  printf( "MCPU lifecycle attributes:\n" );
  printf( "  metadata version:       %u\n", (unsigned int)l->ml_version );
  printf( "  metadata size:          %u\n", (unsigned int)l->ml_size );
  printf( "  lifecycle ABI:          %u\n", (unsigned int)l->ml_abi );
  printf( "  reserved0:              0x%08x\n", (unsigned int)l->ml_reserved0 );
  printf( "  flags:                  0x%016" PRIx64 "\n",
          (uint64_t)l->ml_flags );
  printf( "  reserved1:              0x%016" PRIx64 "\n",
          (uint64_t)l->ml_reserved1 );

} /* End of print_lifecycle() */


static void
print_arch_specific( const readelf_file *m )
{
  size_t i;
  int    printed = 0;

  for( i = 0; i < m->shnum; ++i )
  {
    const readelf_shdr  *sh = &m->shdr[i];
    const unsigned char *payload;
    size_t               payload_size;

    if( sh->type == MELF_SHT_MCPU_TARGET )
    {
      MElf_McpuTarget t;

      if( section_payload( m, i, &payload, &payload_size ) ||
          payload_size != MELF_MCPU_TARGET_SIZE ||
          cpu_melf_decode_target( payload, &t, m->data ) )
      {
        printf( "MCPU target section '%s' is malformed.\n", section_name( m, i ) );
        continue;
      }
      print_target( &t );
      printf( "\n" );
      printed = 1;
    }
    else if( sh->type == MELF_SHT_MCPU_LIFECYCLE )
    {
      MElf_McpuLifecycle l;

      if( section_payload( m, i, &payload, &payload_size ) ||
          payload_size != MELF_MCPU_LIFECYCLE_SIZE ||
          cpu_melf_decode_lifecycle( payload, &l, m->data ) )
      {
        printf( "MCPU lifecycle section '%s' is malformed.\n",
                section_name( m, i ) );
        continue;
      }
      print_lifecycle( &l );
      printf( "\n" );
      printed = 1;
    }
  }

  if( !printed )
    printf( "There are no MCPU architecture-specific metadata sections in this file.\n" );

} /* End of print_arch_specific() */


static int
parse_short_options( const char *arg, readelf_options *opt )
{
  const char *p;

  for( p = arg + 1; *p; ++p )
  {
    switch( *p )
    {
      case 'a':
        opt->file_header = 1;
        opt->program_headers = 1;
        opt->section_headers = 1;
        opt->symbols = 1;
        opt->relocations = 1;
        opt->dynamic = 1;
        opt->arch_specific = 1;
        break;
      case 'e':
        opt->file_header = 1;
        opt->program_headers = 1;
        opt->section_headers = 1;
        break;
      case 'h': opt->file_header = 1; break;
      case 'l': opt->program_headers = 1; break;
      case 'S': opt->section_headers = 1; break;
      case 's': opt->symbols = 1; break;
      case 'r': opt->relocations = 1; break;
      case 'd': opt->dynamic = 1; break;
      case 'A': opt->arch_specific = 1; break;
      case 'W': opt->wide = 1; break;
      default: return( -1 );
    }
  }

  return( 0 );

} /* End of parse_short_options() */


static int
have_output_option( const readelf_options *opt )
{
  return( opt->file_header || opt->program_headers || opt->section_headers ||
          opt->symbols || opt->relocations || opt->dynamic ||
          opt->arch_specific );

} /* End of have_output_option() */


int
main( int argc, char **argv )
{
  readelf_options  opt;
  char           **files;
  size_t           file_count = 0;
  size_t           file_capacity = 0;
  int              i;
  int              rc = 0;

  memset( &opt, 0, sizeof( opt ) );
  files = NULL;

  for( i = 1; i < argc; ++i )
  {
    const char *arg = argv[i];

    if( !strcmp( arg, "--help" ) )
    {
      usage( stdout, argv[0] );
      free( files );
      return( 0 );
    }
    else if( !strcmp( arg, "--version" ) ||
             !strcmp( arg, "--dump-version" ) )
    {
      mcpu_version_action version_action;
      int rc;

      mcpu_version_parse_option( arg, &version_action );
      rc = mcpu_version_print( argv[0], version_action );
      free( files );
      return( rc == 0 ? 0 : 1 );
    }
    else if( !strcmp( arg, "--all" ) )
      parse_short_options( "-a", &opt );
    else if( !strcmp( arg, "--headers" ) )
      parse_short_options( "-e", &opt );
    else if( !strcmp( arg, "--file-header" ) )
      opt.file_header = 1;
    else if( !strcmp( arg, "--program-headers" ) || !strcmp( arg, "--segments" ) )
      opt.program_headers = 1;
    else if( !strcmp( arg, "--section-headers" ) || !strcmp( arg, "--sections" ) )
      opt.section_headers = 1;
    else if( !strcmp( arg, "--symbols" ) || !strcmp( arg, "--syms" ) )
      opt.symbols = 1;
    else if( !strcmp( arg, "--relocs" ) )
      opt.relocations = 1;
    else if( !strcmp( arg, "--dynamic" ) )
      opt.dynamic = 1;
    else if( !strcmp( arg, "--arch-specific" ) )
      opt.arch_specific = 1;
    else if( !strcmp( arg, "--wide" ) )
      opt.wide = 1;
    else if( arg[0] == '-' && arg[1] != '\0' )
    {
      if( parse_short_options( arg, &opt ) )
      {
        fprintf( stderr, "mcpu-readelf: unknown option '%s'\n", arg );
        usage( stderr, argv[0] );
        free( files );
        return( 1 );
      }
    }
    else
    {
      if( file_count == file_capacity )
      {
        size_t  next = file_capacity ? file_capacity * 2U : 4U;
        char  **q = (char **)realloc( files, next * sizeof( *q ) );

        if( !q )
        {
          fprintf( stderr, "mcpu-readelf: out of memory\n" );
          free( files );
          return( 1 );
        }
        files = q;
        file_capacity = next;
      }
      files[file_count++] = argv[i];
    }
  }

  if( !have_output_option( &opt ) || !file_count )
  {
    usage( stderr, argv[0] );
    free( files );
    return( 1 );
  }

  for( i = 0; i < (int)file_count; ++i )
  {
    readelf_file m;
    char         err[512];

    if( file_count > 1 )
      printf( "\nFile: %s\n", files[i] );

    if( readelf_file_open( files[i], &m, err, sizeof( err ) ) )
    {
      fprintf( stderr, "mcpu-readelf: %s\n", err );
      rc = 1;
      continue;
    }

    if( opt.file_header )
    {
      print_file_header( &m );
      if( opt.program_headers || opt.section_headers || opt.symbols ||
          opt.relocations || opt.dynamic || opt.arch_specific )
        printf( "\n" );
    }
    if( opt.program_headers )
    {
      print_program_headers( &m );
      if( opt.section_headers || opt.symbols || opt.relocations ||
          opt.dynamic || opt.arch_specific )
        printf( "\n" );
    }
    if( opt.section_headers )
    {
      print_section_headers( &m );
      if( opt.symbols || opt.relocations || opt.dynamic || opt.arch_specific )
        printf( "\n" );
    }
    if( opt.symbols )
      print_symbols( &m );
    if( opt.relocations )
      print_relocations( &m );
    if( opt.dynamic )
      print_dynamic( &m );
    if( opt.arch_specific )
      print_arch_specific( &m );

    readelf_file_free( &m );
  }

  free( files );
  return( rc );

} /* End of main() */