/*

 * Copyright (c) 2008, 2012, 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-demo.c -- dump a range of addresses as native instructions

   This demonstrates the protocol required by the HotSpot PrintAssembly option.

*/

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <inttypes.h>

#include "hsdis.h"

void greet(const char*);

void disassemble(uintptr_t, uintptr_t);

void end_of_file();

const char* options = NULL;

int         raw     = 0;

int         xml     = 0;

int main(int ac, char** av) {

  int greeted = 0;

  int i;

  for (i = 1; i < ac; i++) {

    const char* arg = av[i];

    if (arg[0] == '-') {

      if (!strcmp(arg, "-xml"))

        xml ^= 1;

      else if (!strcmp(arg, "-raw"))

        raw ^= 1;

      else if (!strncmp(arg, "-options=", 9))

        options = arg+9;

      else

        { printf("Usage: %s [-xml] [name...]\n", av[0]); exit(2); }

      continue;

    }

    greet(arg);

    greeted = 1;

  }

  if (!greeted)

    greet("world");

  printf("...And now for something completely different:\n");

  void *start = (void*) &main;

  void *end = (void*) &end_of_file;

#if defined(__ia64) || defined(__powerpc__)

  /* On IA64 and PPC function pointers are pointers to function descriptors */

  start = *((void**)start);

  end = *((void**)end);

#endif

  disassemble(start, (end > start) ? end : start + 64);

  printf("Cheers!\n");

}

void greet(const char* whom) {

  printf("Hello, %s!\n", whom);

}

void end_of_file() { }

/* don't disassemble after this point... */

#include "dlfcn.h"

#define DECODE_INSTRUCTIONS_VIRTUAL_NAME "decode_instructions_virtual"

#define DECODE_INSTRUCTIONS_NAME "decode_instructions"

#define HSDIS_NAME               "hsdis"

static void* decode_instructions_pv = 0;

static void* decode_instructions_sv = 0;

static const char* hsdis_path[] = {

  HSDIS_NAME"-"LIBARCH LIB_EXT,

  "./" HSDIS_NAME"-"LIBARCH LIB_EXT,

#ifdef TARGET_DIR

  TARGET_DIR"/"HSDIS_NAME"-"LIBARCH LIB_EXT,

#endif

  NULL

};

static const char* load_decode_instructions() {

  void* dllib = NULL;

  const char* *next_in_path = hsdis_path;

  while (1) {

    decode_instructions_pv = dlsym(dllib, DECODE_INSTRUCTIONS_VIRTUAL_NAME);

    decode_instructions_sv = dlsym(dllib, DECODE_INSTRUCTIONS_NAME);

    if (decode_instructions_pv != NULL || decode_instructions_sv != NULL)

      return NULL;

    if (dllib != NULL)

      return "plugin does not defined "DECODE_INSTRUCTIONS_VIRTUAL_NAME" and "DECODE_INSTRUCTIONS_NAME;

    for (dllib = NULL; dllib == NULL; ) {

      const char* next_lib = (*next_in_path++);

      if (next_lib == NULL)

        return "cannot find plugin "HSDIS_NAME LIB_EXT;

      dllib = dlopen(next_lib, RTLD_LAZY);

    }

  }

}

static const char* lookup(void* addr) {

#if defined(__ia64) || defined(__powerpc__)

  /* On IA64 and PPC function pointers are pointers to function descriptors */

#define CHECK_NAME(fn) \

  if (addr == *((void**) &fn))  return #fn;

#else

#define CHECK_NAME(fn) \

  if (addr == (void*) &fn)  return #fn;

#endif

  CHECK_NAME(main);

  CHECK_NAME(greet);

  return NULL;

}

/* does the event match the tag, followed by a null, space, or slash? */

#define MATCH(event, tag) \

  (!strncmp(event, tag, sizeof(tag)-1) && \

   (!event[sizeof(tag)-1] || strchr(" /", event[sizeof(tag)-1])))

static const char event_cookie[] = "event_cookie"; /* demo placeholder */

static void* simple_handle_event(void* cookie, const char* event, void* arg) {

  if (MATCH(event, "/insn")) {

    // follow each complete insn by a nice newline

    printf("\n");

  }

  return NULL;

}

static void* handle_event(void* cookie, const char* event, void* arg) {

#define NS_DEMO "demo:"

  if (cookie != event_cookie)

    printf("*** bad event cookie %p != %p\n", cookie, event_cookie);

  if (xml) {

    /* We could almost do a printf(event, arg),

       but for the sake of a better demo,

       we dress the result up as valid XML.

    */

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

    int evlen = (fmt ? fmt - event : strlen(event));

    if (!fmt) {

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

        printf("<"NS_DEMO"%.*s>", evlen, event);

      } else {

        printf("</"NS_DEMO"%.*s>", evlen-1, event+1);

      }

    } else {

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

        printf("<"NS_DEMO"%.*s", evlen, event);

        printf(fmt, arg);

        printf(">");

      } else {

        printf("<"NS_DEMO"%.*s_done", evlen-1, event+1);

        printf(fmt, arg);

        printf("/></"NS_DEMO"%.*s>", evlen-1, event+1);

      }

    }

  }

  if (MATCH(event, "insn")) {

    const char* name = lookup(arg);

    if (name)  printf("%s:\n", name);

    /* basic action for <insn>: */

    printf(" %p\t", arg);

  } else if (MATCH(event, "/insn")) {

    // follow each complete insn by a nice newline

    printf("\n");

  } else if (MATCH(event, "mach")) {

    printf("Decoding for CPU '%s'\n", (char*) arg);

  } else if (MATCH(event, "addr")) {

    /* basic action for <addr/>: */

    const char* name = lookup(arg);

    if (name) {

      printf("&%s (%p)", name, arg);

      /* return non-null to notify hsdis not to print the addr */

      return arg;

    }

  }

  /* null return is always safe; can mean "I ignored it" */

  return NULL;

}

#define fprintf_callback \

  (decode_instructions_printf_callback_ftype)&fprintf

void disassemble(uintptr_t from, uintptr_t to) {

  const char* err = load_decode_instructions();

  if (err != NULL) {

    printf("%s: %s\n", err, dlerror());

    exit(1);

  }

  decode_func_vtype decode_instructions_v

    = (decode_func_vtype) decode_instructions_pv;

  decode_func_stype decode_instructions_s

    = (decode_func_stype) decode_instructions_sv;

  void* res;

  if (decode_instructions_pv != NULL) {

    printf("\nDecoding from %p to %p...with %s\n", from, to, DECODE_INSTRUCTIONS_VIRTUAL_NAME);

    if (raw) {

      res = (*decode_instructions_v)(from, to,

                                     (unsigned char*)from, to - from,

                                     simple_handle_event, stdout,

                                     NULL, stdout,

                                     options, 0);

    } else {

      res = (*decode_instructions_v)(from, to,

                                    (unsigned char*)from, to - from,

                                     handle_event, (void*) event_cookie,

                                     fprintf_callback, stdout,

                                     options, 0);

    }

    if (res != (void*)to)

      printf("*** Result was %p!\n", res);

  }

  void* sres;

  if (decode_instructions_sv != NULL) {

    printf("\nDecoding from %p to %p...with old decode_instructions\n", from, to, DECODE_INSTRUCTIONS_NAME);

    if (raw) {

      sres = (*decode_instructions_s)(from, to,

                                      simple_handle_event, stdout,

                                      NULL, stdout,

                                      options);

    } else {

      sres = (*decode_instructions_s)(from, to,

                                      handle_event, (void*) event_cookie,

                                      fprintf_callback, stdout,

                                      options);

    }

    if (sres != (void *)to)

      printf("*** Result of decode_instructions %p!\n", sres);

  }

}