/*

 * Copyright (c) 2008, 2019, 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.

 *

 */

#include "precompiled.hpp"

#include "asm/assembler.inline.hpp"

#include "asm/macroAssembler.hpp"

#include "ci/ciUtilities.hpp"

#include "classfile/javaClasses.hpp"

#include "code/codeCache.hpp"

#include "compiler/disassembler.hpp"

#include "gc/shared/cardTable.hpp"

#include "gc/shared/cardTableBarrierSet.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "memory/resourceArea.hpp"

#include "memory/universe.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/handles.inline.hpp"

#include "runtime/os.inline.hpp"

#include "runtime/stubCodeGenerator.hpp"

#include "runtime/stubRoutines.hpp"

#include "utilities/resourceHash.hpp"

#include CPU_HEADER(depChecker)

void*       Disassembler::_library               = NULL;

bool        Disassembler::_tried_to_load_library = false;

bool        Disassembler::_library_usable        = false;

// This routine is in the shared library:

Disassembler::decode_func_virtual Disassembler::_decode_instructions_virtual = NULL;

Disassembler::decode_func Disassembler::_decode_instructions = NULL;

static const char hsdis_library_name[] = "hsdis-" HOTSPOT_LIB_ARCH;

static const char decode_instructions_virtual_name[] = "decode_instructions_virtual";

static const char decode_instructions_name[] = "decode_instructions";

static bool use_new_version = true;

#define COMMENT_COLUMN  52 LP64_ONLY(+8) /*could be an option*/

#define BYTES_COMMENT   ";..."  /* funky byte display comment */

class decode_env {

 private:

  outputStream* _output;      // where the disassembly is directed to

  CodeBuffer*   _codeBuffer;  // != NULL only when decoding a CodeBuffer

  CodeBlob*     _codeBlob;    // != NULL only when decoding a CodeBlob

  nmethod*      _nm;          // != NULL only when decoding a nmethod

  CodeStrings   _strings;

  address       _start;       // != NULL when decoding a range of unknown type

  address       _end;         // != NULL when decoding a range of unknown type

  char          _option_buf[512];

  char          _print_raw;

  address       _cur_insn;        // address of instruction currently being decoded

  int           _bytes_per_line;  // arch-specific formatting option

  int           _pre_decode_alignment;

  int           _post_decode_alignment;

  bool          _print_file_name;

  bool          _print_help;

  bool          _helpPrinted;

  static bool   _optionsParsed;

  enum {

    tabspacing = 8

  };

  // Check if the event matches the expected tag

  // The tag must be a substring of the event, and

  // the tag must be a token in the event, i.e. separated by delimiters

  static bool match(const char* event, const char* tag) {

    size_t eventlen = strlen(event);

    size_t taglen   = strlen(tag);

    if (eventlen < taglen)  // size mismatch

      return false;

    if (strncmp(event, tag, taglen) != 0)  // string mismatch

      return false;

    char delim = event[taglen];

    return delim == '\0' || delim == ' ' || delim == '/' || delim == '=';

  }

  // Merge new option string with previously recorded options

  void collect_options(const char* p) {

    if (p == NULL || p[0] == '\0')  return;

    size_t opt_so_far = strlen(_option_buf);

    if (opt_so_far + 1 + strlen(p) + 1 > sizeof(_option_buf))  return;

    char* fillp = &_option_buf[opt_so_far];

    if (opt_so_far > 0) *fillp++ = ',';

    strcat(fillp, p);

    // replace white space by commas:

    char* q = fillp;

    while ((q = strpbrk(q, " \t\n")) != NULL)

      *q++ = ',';

  }

  void process_options(outputStream* ost);

  void print_insn_labels();

  void print_insn_prefix();

  void print_address(address value);

  // Properly initializes _start/_end. Overwritten too often if

  // printing of instructions is called for each instruction.

  void set_start(address s)   { _start = s; }

  void set_end  (address e)   { _end = e; }

  void set_nm   (nmethod* nm) { _nm = nm; }

  void set_output(outputStream* st) { _output = st; }

#if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)

  // The disassembler library (sometimes) uses tabs to nicely align the instruction operands.

  // Depending on the mnemonic length and the column position where the

  // mnemonic is printed, alignment may turn out to be not so nice.

  // To improve, we assume 8-character tab spacing and left-align the mnemonic on a tab position.

  // Instruction comments are aligned 4 tab positions to the right of the mnemonic.

  void calculate_alignment() {

    _pre_decode_alignment  = ((output()->position()+tabspacing-1)/tabspacing)*tabspacing;

    _post_decode_alignment = _pre_decode_alignment + 4*tabspacing;

  }

  void start_insn(address pc) {

    _cur_insn = pc;

    output()->bol();

    print_insn_labels();

    print_insn_prefix();

  }

  void end_insn(address pc) {

    address pc0 = cur_insn();

    outputStream* st = output();

    if (AbstractDisassembler::show_comment()) {

      if ((_nm != NULL) && _nm->has_code_comment(pc0, pc)) {

        _nm->print_code_comment_on

               (st,

                _post_decode_alignment ? _post_decode_alignment : COMMENT_COLUMN,

                pc0, pc);

        // this calls reloc_string_for which calls oop::print_value_on

      }

      print_hook_comments(pc0, _nm != NULL);

    }

    Disassembler::annotate(pc0, output());

    // follow each complete insn by a nice newline

    st->bol();

  }

#endif

  struct SourceFileInfo {

    struct Link : public CHeapObj<mtCode> {

      const char* file;

      int line;

      Link* next;

      Link(const char* f, int l) : file(f), line(l), next(NULL) {}

    };

    Link *head, *tail;

    static unsigned hash(const address& a) {

      return primitive_hash<address>(a);

    }

    static bool equals(const address& a0, const address& a1) {

      return primitive_equals<address>(a0, a1);

    }

    void append(const char* file, int line) {

      if (tail != NULL && tail->file == file && tail->line == line) {

        // Don't print duplicated lines at the same address. This could happen with C

        // macros that end up having multiple "__" tokens on the same __LINE__.

        return;

      }

      Link *link = new Link(file, line);

      if (head == NULL) {

        head = tail = link;

      } else {

        tail->next = link;

        tail = link;

      }

    }

    SourceFileInfo(const char* file, int line) : head(NULL), tail(NULL) {

      append(file, line);

    }

  };

  typedef ResourceHashtable<

      address, SourceFileInfo,

      SourceFileInfo::hash,

      SourceFileInfo::equals,

      15889,      // prime number

      ResourceObj::C_HEAP> SourceFileInfoTable;

  static SourceFileInfoTable _src_table;

  static const char* _cached_src;

  static GrowableArray<const char*>* _cached_src_lines;

 public:

  decode_env(CodeBuffer* code, outputStream* output);

  decode_env(CodeBlob*   code, outputStream* output, CodeStrings c = CodeStrings() /* , ptrdiff_t offset */);

  decode_env(nmethod*    code, outputStream* output, CodeStrings c = CodeStrings());

  // Constructor for a 'decode_env' to decode an arbitrary

  // piece of memory, hopefully containing code.

  decode_env(address start, address end, outputStream* output);

  // Add 'original_start' argument which is the the original address

  // the instructions were located at (if this is not equal to 'start').

  address decode_instructions(address start, address end, address original_start = NULL);

  address handle_event(const char* event, address arg);

  outputStream* output()   { return _output; }

  address       cur_insn() { return _cur_insn; }

  const char*   options()  { return _option_buf; }

  static void   hook(const char* file, int line, address pc);

  void print_hook_comments(address pc, bool newline);

};

bool decode_env::_optionsParsed = false;

decode_env::SourceFileInfoTable decode_env::_src_table;

const char* decode_env::_cached_src = NULL;

GrowableArray<const char*>* decode_env::_cached_src_lines = NULL;

void decode_env::hook(const char* file, int line, address pc) {

  // For simplication, we never free from this table. It's really not

  // necessary as we add to the table only when PrintInterpreter is true,

  // which means we are debugging the VM and a little bit of extra

  // memory usage doesn't matter.

  SourceFileInfo* found = _src_table.get(pc);

  if (found != NULL) {

    found->append(file, line);

  } else {

    SourceFileInfo sfi(file, line);

    _src_table.put(pc, sfi); // sfi is copied by value

  }

}

void decode_env::print_hook_comments(address pc, bool newline) {

  SourceFileInfo* found = _src_table.get(pc);

  outputStream* st = output();

  if (found != NULL) {

    for (SourceFileInfo::Link *link = found->head; link; link = link->next) {

      const char* file = link->file;

      int line = link->line;

      if (_cached_src == NULL || strcmp(_cached_src, file) != 0) {

        FILE* fp;

        // _cached_src_lines is a single cache of the lines of a source file, and we refill this cache

        // every time we need to print a line from a different source file. It's not the fastest,

        // but seems bearable.

        if (_cached_src_lines != NULL) {

          for (int i=0; i<_cached_src_lines->length(); i++) {

            os::free((void*)_cached_src_lines->at(i));

          }

          _cached_src_lines->clear();

        } else {

          _cached_src_lines = new (ResourceObj::C_HEAP, mtCode)GrowableArray<const char*>(0, true);

        }

        if ((fp = fopen(file, "r")) == NULL) {

          _cached_src = NULL;

          return;

        }

        _cached_src = file;

        char line[500]; // don't write lines that are too long in your source files!

        while (fgets(line, sizeof(line), fp) != NULL) {

          size_t len = strlen(line);

          if (len > 0 && line[len-1] == '\n') {

            line[len-1] = '\0';

          }

          _cached_src_lines->append(os::strdup(line));

        }

        fclose(fp);

        _print_file_name = true;

      }

      if (_print_file_name) {

        // We print the file name whenever we switch to a new file, or when

        // Disassembler::decode is called to disassemble a new block of code.

        _print_file_name = false;

        if (newline) {

          st->cr();

        }

        st->move_to(COMMENT_COLUMN);

        st->print(";;@FILE: %s", file);

        newline = true;

      }

      int index = line - 1; // 1-based line number -> 0-based index.

      if (index >= _cached_src_lines->length()) {

        // This could happen if source file is mismatched.

      } else {

        const char* source_line = _cached_src_lines->at(index);

        if (newline) {

          st->cr();

        }

        st->move_to(COMMENT_COLUMN);

        st->print(";;%5d: %s", line, source_line);

        newline = true;

      }

    }

  }

}

decode_env::decode_env(CodeBuffer* code, outputStream* output) :

  _output(output ? output : tty),

  _codeBuffer(code),

  _codeBlob(NULL),

  _nm(NULL),

  _strings(),

  _start(NULL),

  _end(NULL),

  _option_buf(),

  _print_raw(0),

  _cur_insn(NULL),

  _bytes_per_line(0),

  _pre_decode_alignment(0),

  _post_decode_alignment(0),

  _print_file_name(false),

  _print_help(false),

  _helpPrinted(false) {

  memset(_option_buf, 0, sizeof(_option_buf));

  process_options(_output);

}

decode_env::decode_env(CodeBlob* code, outputStream* output, CodeStrings c) :

  _output(output ? output : tty),

  _codeBuffer(NULL),

  _codeBlob(code),

  _nm(_codeBlob != NULL && _codeBlob->is_nmethod() ? (nmethod*) code : NULL),

  _strings(),

  _start(NULL),

  _end(NULL),

  _option_buf(),

  _print_raw(0),

  _cur_insn(NULL),

  _bytes_per_line(0),

  _pre_decode_alignment(0),

  _post_decode_alignment(0),

  _print_file_name(false),

  _print_help(false),

  _helpPrinted(false) {

  memset(_option_buf, 0, sizeof(_option_buf));

  _strings.copy(c);

  process_options(_output);

}

decode_env::decode_env(nmethod* code, outputStream* output, CodeStrings c) :

  _output(output ? output : tty),

  _codeBuffer(NULL),

  _codeBlob(NULL),

  _nm(code),

  _strings(),

  _start(_nm->code_begin()),

  _end(_nm->code_end()),

  _option_buf(),

  _print_raw(0),

  _cur_insn(NULL),

  _bytes_per_line(0),

  _pre_decode_alignment(0),

  _post_decode_alignment(0),

  _print_file_name(false),

  _print_help(false),

  _helpPrinted(false) {

  memset(_option_buf, 0, sizeof(_option_buf));

  _strings.copy(c);

  process_options(_output);

}

// Constructor for a 'decode_env' to decode a memory range [start, end)

// of unknown origin, assuming it contains code.

decode_env::decode_env(address start, address end, outputStream* output) :

  _output(output ? output : tty),

  _codeBuffer(NULL),

  _codeBlob(NULL),

  _nm(NULL),

  _strings(),

  _start(start),

  _end(end),

  _option_buf(),

  _print_raw(0),

  _cur_insn(NULL),

  _bytes_per_line(0),

  _pre_decode_alignment(0),

  _post_decode_alignment(0),

  _print_file_name(false),

  _print_help(false),

  _helpPrinted(false) {

  assert(start < end, "Range must have a positive size, [" PTR_FORMAT ".." PTR_FORMAT ").", p2i(start), p2i(end));

  memset(_option_buf, 0, sizeof(_option_buf));

  process_options(_output);

}

void decode_env::process_options(outputStream* ost) {

  // by default, output pc but not bytes:

  _print_help      = false;

  _bytes_per_line  = Disassembler::pd_instruction_alignment();

  _print_file_name = true;

  if (_optionsParsed) return;  // parse only once

  // parse the global option string:

  collect_options(Disassembler::pd_cpu_opts());

  collect_options(PrintAssemblyOptions);

  if (strstr(options(), "print-raw")) {

    _print_raw = (strstr(options(), "xml") ? 2 : 1);

  }

  if (strstr(options(), "help")) {

    _print_help = true;

  }

  if (strstr(options(), "align-instr")) {

    AbstractDisassembler::toggle_align_instr();

  }

  if (strstr(options(), "show-pc")) {

    AbstractDisassembler::toggle_show_pc();

  }

  if (strstr(options(), "show-offset")) {

    AbstractDisassembler::toggle_show_offset();

  }

  if (strstr(options(), "show-bytes")) {

    AbstractDisassembler::toggle_show_bytes();

  }

  if (strstr(options(), "show-data-hex")) {

    AbstractDisassembler::toggle_show_data_hex();

  }

  if (strstr(options(), "show-data-int")) {

    AbstractDisassembler::toggle_show_data_int();

  }

  if (strstr(options(), "show-data-float")) {

    AbstractDisassembler::toggle_show_data_float();

  }

  if (strstr(options(), "show-structs")) {

    AbstractDisassembler::toggle_show_structs();

  }

  if (strstr(options(), "show-comment")) {

    AbstractDisassembler::toggle_show_comment();

  }

  if (strstr(options(), "show-block-comment")) {

    AbstractDisassembler::toggle_show_block_comment();

  }

  _optionsParsed = true;

  if (_print_help && ! _helpPrinted) {

    _helpPrinted = true;

    ost->print_cr("PrintAssemblyOptions help:");

    ost->print_cr("  print-raw       test plugin by requesting raw output");

    ost->print_cr("  print-raw-xml   test plugin by requesting raw xml");

    ost->cr();

    ost->print_cr("  show-pc            toggle printing current pc,        currently %s", AbstractDisassembler::show_pc()            ? "ON" : "OFF");

    ost->print_cr("  show-offset        toggle printing current offset,    currently %s", AbstractDisassembler::show_offset()        ? "ON" : "OFF");

    ost->print_cr("  show-bytes         toggle printing instruction bytes, currently %s", AbstractDisassembler::show_bytes()         ? "ON" : "OFF");

    ost->print_cr("  show-data-hex      toggle formatting data as hex,     currently %s", AbstractDisassembler::show_data_hex()      ? "ON" : "OFF");

    ost->print_cr("  show-data-int      toggle formatting data as int,     currently %s", AbstractDisassembler::show_data_int()      ? "ON" : "OFF");

    ost->print_cr("  show-data-float    toggle formatting data as float,   currently %s", AbstractDisassembler::show_data_float()    ? "ON" : "OFF");

    ost->print_cr("  show-structs       toggle compiler data structures,   currently %s", AbstractDisassembler::show_structs()       ? "ON" : "OFF");

    ost->print_cr("  show-comment       toggle instruction comments,       currently %s", AbstractDisassembler::show_comment()       ? "ON" : "OFF");

    ost->print_cr("  show-block-comment toggle block comments,             currently %s", AbstractDisassembler::show_block_comment() ? "ON" : "OFF");

    ost->print_cr("  align-instr        toggle instruction alignment,      currently %s", AbstractDisassembler::align_instr()        ? "ON" : "OFF");

    ost->print_cr("combined options: %s", options());

  }

}

// Disassembly Event Handler.

// This method receives events from the disassembler library hsdis

// via event_to_env for each decoding step (installed by

// Disassembler::decode_instructions(), replacing the default

// callback method). This enables dumping additional info

// and custom line formatting.

// In a future extension, calling a custom decode method will be

// supported. We can use such a method to decode instructions the

// binutils decoder does not handle to our liking (suboptimal

// formatting, incomplete information, ...).

// Returns:

// - NULL for all standard invocations. The function result is not

//        examined (as of now, 20190409) by the hsdis decoder loop.

// - next for 'insn0' invocations.