/*

 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2019 SAP SE. 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.

 *

 */

// AbstractDisassembler is the base class for

// platform-specific Disassembler classes.

#include "precompiled.hpp"

#include "asm/assembler.inline.hpp"

#include "compiler/abstractDisassembler.hpp"

#include "oops/oop.inline.hpp"

#include "utilities/debug.hpp"

#include "utilities/ostream.hpp"

// Default values for what is being printed as line prefix when disassembling a single instruction.

// Can be overridden by command line parameter PrintAssemblyOptions.

bool AbstractDisassembler::_show_data_hex      = true;

bool AbstractDisassembler::_show_data_int      = false;

bool AbstractDisassembler::_show_data_float    = false;

bool AbstractDisassembler::_show_pc            = true;

bool AbstractDisassembler::_show_offset        = false;

// set "true" to see what's in memory bit by bit

// might prove cumbersome on platforms where instr_len is hard to find out

bool AbstractDisassembler::_show_bytes         = false;

// Return #bytes printed. Callers may use that for output alignment.

// Print instruction address, and offset from blob begin.

// Offset width (2, 4, 6, 8 bytes) is adapted to size of blob.

// Working assumption: we are at st->bol() upon entry. If not, it's the

//                     caller's responsibility to guarantee proper alignment.

int AbstractDisassembler::print_location(address here, address begin, address end, outputStream* st, bool align, bool print_header) {

  const int     pos_0  = st->position();

  if (show_pc() || show_offset()) {

    st->print(" ");

  }

  if (show_pc()) {

    if (print_header) {

      st->print(" %*s", 18, "Address");

    } else {

      st->print(" " PTR_FORMAT, p2i(here));

    }

  }

  if (show_offset()) {

#ifdef ASSERT

    if ((uintptr_t)begin > (uintptr_t)here) st->print(">>begin(" PTR_FORMAT ") > here(" PTR_FORMAT ")<<", p2i(begin), p2i(here));

    if ((uintptr_t)end   < (uintptr_t)here) st->print(">>  end(" PTR_FORMAT ") < here(" PTR_FORMAT ")<<", p2i(end),   p2i(here));

    assert((uintptr_t)begin <= (uintptr_t)end, "inverted address range");

#endif

    const int blob_len = end - begin;

    const int offset   = here - begin;

    const int width    = (blob_len < (1<< 8)) ? 2 : (blob_len < (1<<16)) ? 4 : (blob_len < (1<<24)) ? 6 : 8;

    if (print_header) {

      st->print(" %*s", width+5, "offset");

    } else {

      st->print(" (+0x%*.*x)", width, width, offset);

    }

  }

  if ((show_pc() || show_offset()) && !print_header) {

    st->print(": ");

  }

  if (align) {

    const uint tabspacing  = 8;

    const uint pos         = st->position();

    const uint aligned_pos = ((pos+tabspacing-1)/tabspacing)*tabspacing /* - 1 */;

    st->fill_to(aligned_pos);

  }

  return st->position() - pos_0;

}

// Return #bytes printed. Callers may use that for output alignment.

// Print instruction in hexadecimal representation, using 2-byte blocks.

// Used with real disassemblies. Not so useful with abstract disassemblies.

int AbstractDisassembler::print_instruction(address here, int len, int max_len, outputStream* st, bool align, bool print_header) {

  if (show_bytes()) {

    const int block_bytes = 2;

    const int pos_0       = st->position();

    address   pos         = here;

    //---<  print instruction bytes in blocks  >---

    // must print byte by byte: address might be unaligned.

    for (; pos <= here + len - block_bytes; pos += block_bytes) {

      for (address byte = pos; byte < pos + block_bytes; byte++) {

        st->print("%2.2x", *byte);

      }

      st->print(" ");

    }

    //---<  Print the remaining bytes of the instruction  >---

    if ((len & (block_bytes - 1)) != 0) {

      for (; pos < here + len; pos++) {

        st->print("%2.2x", *pos);

      }

    }

    //---<  filler for shorter than max_len instructions  >---

    for (int i = len+1; i < max_len; i++) {

      st->print("  ");

    }

    st->print(" "); // separator space.

    print_delimiter(st);

    return st->position() - pos_0;

  }

  if (align) {

    const uint tabspacing  = 8;

    const uint pos         = st->position();

    const uint aligned_pos = ((pos+tabspacing-1)/tabspacing)*tabspacing /* - 1 */;

    st->fill_to(aligned_pos);

  }

  return 0;

}

// Return #bytes printed. Callers may use that for output alignment.

// Print data (e.g. constant pool entries) in hex format.

// Depending on the alignment, short, int, and long entities are printed.

// If selected, data is formatted as int/long and float/double values in addition.

int AbstractDisassembler::print_hexdata(address here, int len, outputStream* st, bool print_header) {

  const int tsize = 8;

  const int pos_0 = st->position();

  int pos   = pos_0;

  int align = ((pos+tsize-1)/tsize)*tsize;

  st->fill_to(align);

  //---<  printing hex data  >---

  if (show_data_hex()) {

    switch (len) {

      case 1: if (print_header) {

                st->print("hex1");

              } else {

                st->print("0x%02x", *here);

              }

              st->fill_to(align += tsize);

      case 2: if (print_header) {

                st->print("  hex2");

              } else {

                if (((uintptr_t)(here)&0x01) == 0) {

                  st->print("0x%04x",   *((jushort*)here));

                }

              }

              st->fill_to(align += tsize);

      case 4: if (print_header) {

                st->print("      hex4");

              } else {

                if (((uintptr_t)(here)&0x03) == 0) {

                  st->print("0x%08x",   *((juint*)here));

                }

              }

              st->fill_to(align += 2*tsize);

      case 8: if (print_header) {

                st->print("              hex8");

              } else {

                if (((uintptr_t)(here)&0x07) == 0) {

                  st->print(PTR_FORMAT, *((uintptr_t*)here));

                }

              }

              st->fill_to(align += 3*tsize);

              break;

      default: ;

    }

    pos   = st->position();

    align = ((pos+tsize-1)/tsize)*tsize;

    st->fill_to(align);

  }

  //---<  printing int/long data  >---

  if (show_data_int()) {

    switch (len) {

      case 4: if (print_header) {

                st->print("         int");

              } else {

                if (((uintptr_t)(here)&0x03) == 0) {

                  st->print("%12.1d",  *((jint*)here));

                }

              }

              st->fill_to(align += 2*tsize);

      case 8: if (print_header) {

                st->print("                   long");

              } else {

                if (((uintptr_t)(here)&0x07) == 0) {

                  st->print(JLONG_FORMAT_W(23), *((jlong*)here));

                }

              }

              st->fill_to(align += 3*tsize);

              break;

      default: ;

    }

    pos   = st->position();

    align = ((pos+tsize-1)/tsize)*tsize;

    st->fill_to(align);

  }

  //---<  printing float/double data  >---

  if (show_data_float()) {

    switch (len) {

      case 4: if (print_header) {

                st->print("          float");

              } else {

                if (((uintptr_t)(here)&0x03) == 0) {

                  st->print("%15.7e",  (double)*((float*)here));

                }

              }

              st->fill_to(align += 2*tsize);

      case 8: if (print_header) {

                st->print("                 double");

              } else {

                if (((uintptr_t)(here)&0x07) == 0) {

                  st->print("%23.15e",         *((double*)here));

                }

              }

              st->fill_to(align += 3*tsize);

              break;

      default: ;

    }

  }

  return st->position() - pos_0;

}

// Return #bytes printed. Callers may use that for output alignment.

// Print an instruction delimiter.

int AbstractDisassembler::print_delimiter(outputStream* st) {

  if (align_instr()) { st->print("| "); return 2; }

  else               return 0;

}

// Decodes the one instruction at address start in a platform-independent format.

// Returns the start of the next instruction (which is 'start' plus 'instruction_size_in_bytes').

// The parameter max_instr_size_in_bytes is used for output alignment purposes only.

address AbstractDisassembler::decode_instruction_abstract(address start,

                                                          outputStream* st,

                                                          const int instruction_size_in_bytes,

                                                          const int max_instr_size_in_bytes) {

  assert(instruction_size_in_bytes > 0, "no zero-size instructions!");

  assert(max_instr_size_in_bytes >= instruction_size_in_bytes, "inconsistent call parameters");

  //---<  current instruction is at the start address  >---

  unsigned char* current = (unsigned char*) start;

  int            filler_limit = align_instr() ? max_instr_size_in_bytes : ((instruction_size_in_bytes+abstract_instruction_bytes_per_block-1)/abstract_instruction_bytes_per_block)

                                                                          *abstract_instruction_bytes_per_block;

  //---<  print the instruction's bytes  >---

  for (int i = 1; i <= instruction_size_in_bytes; i++) {

    st->print("%02x", *current);

    ++current;

    if (abstract_instruction_bytes_per_block <= max_instr_size_in_bytes) {

      if (i%abstract_instruction_bytes_per_block == 0) st->print(" ");

    } else {

      if (i == instruction_size_in_bytes) st->print(" ");

    }

  }

  //---<  print some filler spaces to column-align instructions  >---

  for (int i = instruction_size_in_bytes+1; i <= filler_limit; i++) {

    st->print("  ");

    if (abstract_instruction_bytes_per_block <= max_instr_size_in_bytes) {

      if (i%abstract_instruction_bytes_per_block == 0) st->print(" ");

    } else {

      if (i == instruction_size_in_bytes) st->print(" ");

    }

  }

  //---<  the address of the next instruction  >---

  return (address) current;

}

// Decodes all instructions in the given range [start..end)

// calling decode_instruction_abstract for each instruction.

// The format is platform dependent only to the extend that

// it respects the actual instruction length where possible.

// Does not print any markers or decorators.

void AbstractDisassembler::decode_range_abstract(address range_start, address range_end,

                                                 address start, address end,

                                                 outputStream* st,

                                                 const int max_instr_size_in_bytes) {

  assert(st != NULL, "need an output stream (no default)!");

  int     idx = 0;

  address pos = range_start;

  while ((pos != NULL) && (pos < range_end)) {

    int instr_size_in_bytes = Assembler::instr_len(pos);

    if (idx == 0) print_location(pos, start, end, st, false, false);

    else          print_delimiter(st);

    //---<  print the instruction's bytes  >---

    // don't access storage beyond end of range

    if (pos + instr_size_in_bytes <= range_end) {

      pos = decode_instruction_abstract(pos, st, instr_size_in_bytes, max_instr_size_in_bytes);

    } else {

      // If the range to be decoded contains garbage at the end (e.g. 0xcc initializer bytes),

      // instruction size calculation may run out of sync. Just terminate in that case.

      pos = range_end;

    }

    idx += instr_size_in_bytes;

    if (start_newline(idx)) {

      st->cr();

      idx = 0;

    }

  }

}

// Decodes all instructions in the given range [start..end).

// The output is enclosed in [MachCode] and [/MachCode] tags for later recognition.

// The format is platform dependent only to the extend that

// it respects the actual instruction length where possible.

void AbstractDisassembler::decode_abstract(address start, address end, outputStream* ost,

                                           const int max_instr_size_in_bytes) {

  int     idx = 0;

  address pos = start;

  outputStream* st = (ost == NULL) ? tty : ost;

  //---<  Open the output (Marker for post-mortem disassembler)  >---

  st->bol();

  st->print_cr("[MachCode]");

  decode_range_abstract(start, end, start, end, st, max_instr_size_in_bytes);

  //---<  Close the output (Marker for post-mortem disassembler)  >---

  st->bol();

  st->print_cr("[/MachCode]");

}