/*

 * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

/* hsdis.c -- dump a range of addresses as native instructions

   This implements the plugin protocol required by the

   HotSpot PrintAssembly option.

*/

#include "hsdis.h"

#include <sysdep.h>

#include <libiberty.h>

#include <bfd.h>

#include <dis-asm.h>

#include <inttypes.h>

#ifndef bool

#define bool int

#define true 1

#define false 0

#endif /*bool*/

/* short names for stuff in hsdis.h */

typedef decode_instructions_event_callback_ftype  event_callback_t;

typedef decode_instructions_printf_callback_ftype printf_callback_t;

/* disassemble_info.application_data object */

struct hsdis_app_data {

  /* the arguments to decode_instructions */

  uintptr_t start; uintptr_t end;

  event_callback_t  event_callback;  void* event_stream;

  printf_callback_t printf_callback; void* printf_stream;

  bool losing;

  /* the architecture being disassembled */

  const char* arch_name;

  const bfd_arch_info_type* arch_info;

  /* the disassembler we are going to use: */

  disassembler_ftype      dfn;

  struct disassemble_info dinfo; /* the actual struct! */

  char mach_option[64];

  char insn_options[256];

};

#define DECL_APP_DATA(dinfo) \

  struct hsdis_app_data* app_data = (struct hsdis_app_data*) (dinfo)->application_data

#define DECL_EVENT_CALLBACK(app_data) \

  event_callback_t  event_callback = (app_data)->event_callback; \

  void*             event_stream   = (app_data)->event_stream

#define DECL_PRINTF_CALLBACK(app_data) \

  printf_callback_t  printf_callback = (app_data)->printf_callback; \

  void*              printf_stream   = (app_data)->printf_stream

static void print_help(struct hsdis_app_data* app_data,

                       const char* msg, const char* arg);

static void setup_app_data(struct hsdis_app_data* app_data,

                           const char* options);

static const char* format_insn_close(const char* close,

                                     disassemble_info* dinfo,

                                     char* buf, size_t bufsize);

void*

#ifdef DLL_ENTRY

  DLL_ENTRY

#endif

decode_instructions(void* start_pv, void* end_pv,

                    event_callback_t  event_callback_arg,  void* event_stream_arg,

                    printf_callback_t printf_callback_arg, void* printf_stream_arg,

                    const char* options) {

  struct hsdis_app_data app_data;

  memset(&app_data, 0, sizeof(app_data));

  app_data.start = (uintptr_t) start_pv;

  app_data.end   = (uintptr_t) end_pv;

  app_data.event_callback  = event_callback_arg;

  app_data.event_stream    = event_stream_arg;

  app_data.printf_callback = printf_callback_arg;

  app_data.printf_stream   = printf_stream_arg;

  setup_app_data(&app_data, options);

  char buf[128];

  {

    /* now reload everything from app_data: */

    DECL_EVENT_CALLBACK(&app_data);

    DECL_PRINTF_CALLBACK(&app_data);

    uintptr_t start = app_data.start;

    uintptr_t end   = app_data.end;

    uintptr_t p     = start;

    (*event_callback)(event_stream, "insns", (void*)start);

    (*event_callback)(event_stream, "mach name='%s'",

                      (void*) app_data.arch_info->printable_name);

    if (app_data.dinfo.bytes_per_line != 0) {

      (*event_callback)(event_stream, "format bytes-per-line='%p'/",

                        (void*)(intptr_t) app_data.dinfo.bytes_per_line);

    }

    while (p < end && !app_data.losing) {

      (*event_callback)(event_stream, "insn", (void*) p);

      /* reset certain state, so we can read it with confidence */

      app_data.dinfo.insn_info_valid    = 0;

      app_data.dinfo.branch_delay_insns = 0;

      app_data.dinfo.data_size          = 0;

      app_data.dinfo.insn_type          = 0;

      int size = (*app_data.dfn)((bfd_vma) p, &app_data.dinfo);

      if (size > 0)  p += size;

      else           app_data.losing = true;

      const char* insn_close = format_insn_close("/insn", &app_data.dinfo,

                                                 buf, sizeof(buf));

      (*event_callback)(event_stream, insn_close, (void*) p);

      /* follow each complete insn by a nice newline */

      (*printf_callback)(printf_stream, "\n");

    }

    (*event_callback)(event_stream, "/insns", (void*) p);

    return (void*) p;

  }

}

/* take the address of the function, for luck, and also test the typedef: */

const decode_instructions_ftype decode_instructions_address = &decode_instructions;

static const char* format_insn_close(const char* close,

                                     disassemble_info* dinfo,

                                     char* buf, size_t bufsize) {

  if (!dinfo->insn_info_valid)

    return close;

  enum dis_insn_type itype = dinfo->insn_type;

  int dsize = dinfo->data_size, delays = dinfo->branch_delay_insns;

  if ((itype == dis_nonbranch && (dsize | delays) == 0)

      || (strlen(close) + 3*20 > bufsize))

    return close;

  const char* type = "unknown";

  switch (itype) {

  case dis_nonbranch:   type = NULL;         break;

  case dis_branch:      type = "branch";     break;

  case dis_condbranch:  type = "condbranch"; break;

  case dis_jsr:         type = "jsr";        break;

  case dis_condjsr:     type = "condjsr";    break;

  case dis_dref:        type = "dref";       break;

  case dis_dref2:       type = "dref2";      break;

  }

  strcpy(buf, close);

  char* p = buf;

  if (type)    sprintf(p += strlen(p), " type='%s'", type);

  if (dsize)   sprintf(p += strlen(p), " dsize='%d'", dsize);

  if (delays)  sprintf(p += strlen(p), " delay='%d'", delays);

  return buf;

}

/* handler functions */

static int

hsdis_read_memory_func(bfd_vma memaddr,

                       bfd_byte* myaddr,

                       unsigned int length,

                       struct disassemble_info* dinfo) {

  uintptr_t memaddr_p = (uintptr_t) memaddr;

  DECL_APP_DATA(dinfo);

  if (memaddr_p + length > app_data->end) {

    /* read is out of bounds */

    return EIO;

  } else {

    memcpy(myaddr, (bfd_byte*) memaddr_p, length);

    return 0;

  }

}

static void

hsdis_print_address_func(bfd_vma vma, struct disassemble_info* dinfo) {

  /* the actual value to print: */

  void* addr_value = (void*) (uintptr_t) vma;

  DECL_APP_DATA(dinfo);

  DECL_EVENT_CALLBACK(app_data);

  /* issue the event: */

  void* result =

    (*event_callback)(event_stream, "addr/", addr_value);

  if (result == NULL) {

    /* event declined */

    generic_print_address(vma, dinfo);

  }

}

/* configuration */

static void set_optional_callbacks(struct hsdis_app_data* app_data);

static void parse_caller_options(struct hsdis_app_data* app_data,

                                 const char* caller_options);

static const char* native_arch_name();

static enum bfd_endian native_endian();

static const bfd_arch_info_type* find_arch_info(const char* arch_nane);

static bfd* get_native_bfd(const bfd_arch_info_type* arch_info,

                           /* to avoid malloc: */

                           bfd* empty_bfd, bfd_target* empty_xvec);

static void init_disassemble_info_from_bfd(struct disassemble_info* dinfo,

                                           void *stream,

                                           fprintf_ftype fprintf_func,

                                           bfd* bfd,

                                           char* disassembler_options);

static void parse_fake_insn(disassembler_ftype dfn,

                            struct disassemble_info* dinfo);

static void setup_app_data(struct hsdis_app_data* app_data,

                           const char* caller_options) {

  /* Make reasonable defaults for null callbacks.

     A non-null stream for a null callback is assumed to be a FILE* for output.

     Events are rendered as XML.

  */

  set_optional_callbacks(app_data);

  /* Look into caller_options for anything interesting. */

  if (caller_options != NULL)

    parse_caller_options(app_data, caller_options);

  /* Discover which architecture we are going to disassemble. */

  app_data->arch_name = &app_data->mach_option[0];

  if (app_data->arch_name[0] == '\0')

    app_data->arch_name = native_arch_name();

  app_data->arch_info = find_arch_info(app_data->arch_name);

  /* Make a fake bfd to hold the arch. and byteorder info. */

  struct {

    bfd_target empty_xvec;

    bfd        empty_bfd;

  } buf;

  bfd* native_bfd = get_native_bfd(app_data->arch_info,

                                   /* to avoid malloc: */

                                   &buf.empty_bfd, &buf.empty_xvec);

  init_disassemble_info_from_bfd(&app_data->dinfo,

                                 app_data->printf_stream,

                                 app_data->printf_callback,

                                 native_bfd,

                                 app_data->insn_options);

  /* Finish linking together the various callback blocks. */

  app_data->dinfo.application_data = (void*) app_data;

  app_data->dfn = disassembler(native_bfd);

  app_data->dinfo.print_address_func = hsdis_print_address_func;

  app_data->dinfo.read_memory_func = hsdis_read_memory_func;

  if (app_data->dfn == NULL) {

    const char* bad = app_data->arch_name;

    static bool complained;

    if (bad == &app_data->mach_option[0])

      print_help(app_data, "bad mach=%s", bad);

    else if (!complained)

      print_help(app_data, "bad native mach=%s; please port hsdis to this platform", bad);

    complained = true;

    /* must bail out */

    app_data->losing = true;

    return;

  }

  parse_fake_insn(app_data->dfn, &app_data->dinfo);

}

/* ignore all events, return a null */

static void* null_event_callback(void* ignore_stream, const char* ignore_event, void* arg) {

  return NULL;

}

/* print all events as XML markup */

static void* xml_event_callback(void* stream, const char* event, void* arg) {

  FILE* fp = (FILE*) stream;

#define NS_PFX "dis:"

  if (event[0] != '/') {

    /* issue the tag, with or without a formatted argument */

    fprintf(fp, "<"NS_PFX);

    fprintf(fp, event, arg);

    fprintf(fp, ">");

  } else {

    ++event;                    /* skip slash */

    const char* argp = strchr(event, ' ');

    if (argp == NULL) {

      /* no arguments; just issue the closing tag */

      fprintf(fp, "</"NS_PFX"%s>", event);

    } else {

      /* split out the closing attributes as <dis:foo_done attr='val'/> */

      int event_prefix = (argp - event);

      fprintf(fp, "<"NS_PFX"%.*s_done", event_prefix, event);

      fprintf(fp, argp, arg);

      fprintf(fp, "/></"NS_PFX"%.*s>", event_prefix, event);

    }

  }

  return NULL;

}

static void set_optional_callbacks(struct hsdis_app_data* app_data) {

  if (app_data->printf_callback == NULL) {

    int (*fprintf_callback)(FILE*, const char*, ...) = &fprintf;

    FILE* fprintf_stream = stdout;

    app_data->printf_callback = (printf_callback_t) fprintf_callback;

    if (app_data->printf_stream == NULL)

      app_data->printf_stream   = (void*)           fprintf_stream;

  }

  if (app_data->event_callback == NULL) {

    if (app_data->event_stream == NULL)

      app_data->event_callback = &null_event_callback;

    else

      app_data->event_callback = &xml_event_callback;

  }

}

static void parse_caller_options(struct hsdis_app_data* app_data, const char* caller_options) {

  char* iop_base = app_data->insn_options;

  char* iop_limit = iop_base + sizeof(app_data->insn_options) - 1;

  char* iop = iop_base;

  const char* p;

  for (p = caller_options; p != NULL; ) {

    const char* q = strchr(p, ',');

    size_t plen = (q == NULL) ? strlen(p) : ((q++) - p);

    if (plen == 4 && strncmp(p, "help", plen) == 0) {

      print_help(app_data, NULL, NULL);

    } else if (plen >= 5 && strncmp(p, "mach=", 5) == 0) {

      char*  mach_option = app_data->mach_option;

      size_t mach_size   = sizeof(app_data->mach_option);

      mach_size -= 1;           /*leave room for the null*/

      if (plen > mach_size)  plen = mach_size;

      strncpy(mach_option, p, plen);

      mach_option[plen] = '\0';

    } else if (plen > 6 && strncmp(p, "hsdis-", 6) == 0) {

      // do not pass these to the next level

    } else {

      /* just copy it; {i386,sparc}-dis.c might like to see it  */

      if (iop > iop_base && iop < iop_limit)  (*iop++) = ',';

      if (iop + plen > iop_limit)

        plen = iop_limit - iop;

      strncpy(iop, p, plen);

      iop += plen;

    }

    p = q;

  }

}

static void print_help(struct hsdis_app_data* app_data,

                       const char* msg, const char* arg) {

  DECL_PRINTF_CALLBACK(app_data);

  if (msg != NULL) {

    (*printf_callback)(printf_stream, "hsdis: ");

    (*printf_callback)(printf_stream, msg, arg);

    (*printf_callback)(printf_stream, "\n");

  }

  (*printf_callback)(printf_stream, "hsdis output options:\n");

  if (printf_callback == (printf_callback_t) &fprintf)

    disassembler_usage((FILE*) printf_stream);

  else

    disassembler_usage(stderr); /* better than nothing */

  (*printf_callback)(printf_stream, "  mach=<arch>   select disassembly mode\n");

#if defined(LIBARCH_i386) || defined(LIBARCH_amd64)

  (*printf_callback)(printf_stream, "  mach=i386     select 32-bit mode\n");

  (*printf_callback)(printf_stream, "  mach=x86-64   select 64-bit mode\n");

  (*printf_callback)(printf_stream, "  suffix        always print instruction suffix\n");

#endif

  (*printf_callback)(printf_stream, "  help          print this message\n");

}

/* low-level bfd and arch stuff that binutils doesn't do for us */

static const bfd_arch_info_type* find_arch_info(const char* arch_name) {

  const bfd_arch_info_type* arch_info = bfd_scan_arch(arch_name);

  if (arch_info == NULL) {

    extern const bfd_arch_info_type bfd_default_arch_struct;

    arch_info = &bfd_default_arch_struct;

  }

  return arch_info;

}

static const char* native_arch_name() {

  const char* res = NULL;

#ifdef LIBARCH_i386

    res = "i386";

#endif

#ifdef LIBARCH_amd64

    res = "i386:x86-64";

#endif

#ifdef LIBARCH_sparc

    res = "sparc:v8plusb";

#endif

#ifdef LIBARCH_sparcv9

    res = "sparc:v9b";

#endif

  if (res == NULL)

    res = "architecture not set in Makefile!";

  return res;

}

static enum bfd_endian native_endian() {

  int32_t endian_test = 'x';

  if (*(const char*) &endian_test == 'x')

    return BFD_ENDIAN_LITTLE;

  else

    return BFD_ENDIAN_BIG;

}

static bfd* get_native_bfd(const bfd_arch_info_type* arch_info,

                           bfd* empty_bfd, bfd_target* empty_xvec) {

  memset(empty_bfd,  0, sizeof(*empty_bfd));

  memset(empty_xvec, 0, sizeof(*empty_xvec));

  empty_xvec->flavour = bfd_target_unknown_flavour;

  empty_xvec->byteorder = native_endian();

  empty_bfd->xvec = empty_xvec;

  empty_bfd->arch_info = arch_info;

  return empty_bfd;

}

static int read_zero_data_only(bfd_vma ignore_p,

                               bfd_byte* myaddr, unsigned int length,

                               struct disassemble_info *ignore_info) {

  memset(myaddr, 0, length);

  return 0;

}

static int print_to_dev_null(void* ignore_stream, const char* ignore_format, ...) {

  return 0;

}

/* Prime the pump by running the selected disassembler on a null input.

   This forces the machine-specific disassembler to divulge invariant

   information like bytes_per_line.

 */

static void parse_fake_insn(disassembler_ftype dfn,

                            struct disassemble_info* dinfo) {

  typedef int (*read_memory_ftype)

    (bfd_vma memaddr, bfd_byte *myaddr, unsigned int length,

     struct disassemble_info *info);

  read_memory_ftype read_memory_func = dinfo->read_memory_func;

  fprintf_ftype     fprintf_func     = dinfo->fprintf_func;

  dinfo->read_memory_func = &read_zero_data_only;

  dinfo->fprintf_func     = &print_to_dev_null;

  (*dfn)(0, dinfo);

  // put it back:

  dinfo->read_memory_func = read_memory_func;

  dinfo->fprintf_func     = fprintf_func;

}

static void init_disassemble_info_from_bfd(struct disassemble_info* dinfo,

                                           void *stream,

                                           fprintf_ftype fprintf_func,

                                           bfd* abfd,

                                           char* disassembler_options) {

  init_disassemble_info(dinfo, stream, fprintf_func);

  dinfo->flavour = bfd_get_flavour(abfd);

  dinfo->arch = bfd_get_arch(abfd);

  dinfo->mach = bfd_get_mach(abfd);

  dinfo->disassembler_options = disassembler_options;

  dinfo->octets_per_byte = bfd_octets_per_byte (abfd);

  dinfo->skip_zeroes = sizeof(void*) * 2;

  dinfo->skip_zeroes_at_end = sizeof(void*)-1;

  dinfo->disassembler_needs_relocs = FALSE;

  if (bfd_big_endian(abfd))

    dinfo->display_endian = dinfo->endian = BFD_ENDIAN_BIG;

  else if (bfd_little_endian(abfd))

    dinfo->display_endian = dinfo->endian = BFD_ENDIAN_LITTLE;

  else

    dinfo->endian = native_endian();

  disassemble_init_for_target(dinfo);

}