path: root/dev/CompilerKit/src/Backend/Assembler64x0.cc

/* -------------------------------------------

  Copyright (C) 2024-2025 Amlal EL Mahrouss, Licensed under Apache 2.0

------------------------------------------- */

/// bugs: 0

/////////////////////////////////////////////////////////////////////////////////////////

// @file Assembler64x0.cc
// @author Amlal El Mahrouss
// @brief 64x000 Assembler.

// REMINDER: when dealing with an undefined symbol use (string
// size):LinkerFindSymbol:(string) so that ld will look for it.

/////////////////////////////////////////////////////////////////////////////////////////

#ifndef __ASM_NEED_64x0__
#define __ASM_NEED_64x0__ 1
#endif

#include <CompilerKit/AE.h>
#include <CompilerKit/Frontend.h>
#include <CompilerKit/PEF.h>
#include <CompilerKit/impl/64x0.h>
#include <CompilerKit/utils/CompilerUtils.h>
#include <algorithm>
#include <filesystem>
#include <fstream>
#include <iostream>
#include <vector>

/////////////////////

// ANSI ESCAPE CODES

/////////////////////

static char kOutputArch = CompilerKit::kPefArch64000;

constexpr auto k64x0IPAlignment = 0x1U;

static std::size_t kCounter = 1UL;

static std::uintptr_t                                      kOrigin = kPefBaseOrigin;
static std::vector<std::pair<std::string, std::uintptr_t>> kOriginLabel;

static std::vector<e64k_num_t> kBytes;

static CompilerKit::AERecordHeader kCurrentRecord{
    .fName = "", .fKind = CompilerKit::kPefCode, .fSize = 0, .fOffset = 0};

static std::vector<CompilerKit::AERecordHeader> kRecords;
static std::vector<std::string>                 kUndefinedSymbols;

static const std::string kUndefinedSymbol = ":UndefinedSymbol:";
static const std::string kRelocSymbol     = ":RuntimeSymbol:";

// \brief forward decl.
static bool asm_read_attributes(std::string line);

/////////////////////////////////////////////////////////////////////////////////////////

// @brief 64x0 assembler entrypoint, the program/module starts here.

/////////////////////////////////////////////////////////////////////////////////////////

NECTI_MODULE(AssemblerMain64x0) {
  CompilerKit::install_signal(SIGSEGV, Detail::drvi_crash_handler);

  for (size_t i = 1; i < argc; ++i) {
    if (argv[i][0] == '-') {
      if (strcmp(argv[i], "-64x0-ver") == 0 || strcmp(argv[i], "-64x0-v") == 0) {
        kStdOut
            << "Assembler64x0: 64x0 Assembler.\nAssembler64x0: v1.10\nAssembler64x0: Copyright (c) "
               "Amlal El Mahrouss\n";
        return 0;
      } else if (strcmp(argv[i], "-64x0-h") == 0) {
        kStdOut << "Assembler64x0: 64x0 Assembler.\nAssembler64x0: Copyright (c) 2024 Mahrouss "
                   "Logic.\n";
        kStdOut << "--version: Print program version.\n";
        kStdOut << "--verbose: Print verbose output.\n";
        kStdOut << "--binary: Output as flat binary.\n";
        kStdOut << "--64xxx: Compile for a subset of the X64000.\n";

        return 0;
      } else if (strcmp(argv[i], "-64x0-binary") == 0) {
        kOutputAsBinary = true;
        continue;
      } else if (strcmp(argv[i], "-64x0-verbose") == 0) {
        kVerbose = true;
        continue;
      }

      kStdOut << "Assembler64x0: ignore " << argv[i] << "\n";
      continue;
    }

    if (!std::filesystem::exists(argv[i])) {
      kStdOut << "Assembler64x0: can't open: " << argv[i] << std::endl;
      goto asm_fail_exit;
    }

    std::string object_output(argv[i]);

    for (auto& ext : kAsmFileExts) {
      if (object_output.find(ext) != std::string::npos) {
        object_output.erase(object_output.find(ext), std::strlen(ext));
      }
    }

    object_output += kOutputAsBinary ? kBinaryFileExt : kObjectFileExt;

    std::ifstream file_ptr(argv[i]);
    std::ofstream file_ptr_out(object_output, std::ofstream::binary);

    if (file_ptr_out.bad()) {
      if (kVerbose) {
        kStdOut << "Assembler64x0: error: " << strerror(errno) << "\n";
      }
    }

    std::string line;

    CompilerKit::AEHeader hdr{0};

    memset(hdr.fPad, kAENullType, kAEPad);

    hdr.fMagic[0] = kAEMag0;
    hdr.fMagic[1] = kAEMag1;
    hdr.fSize     = sizeof(CompilerKit::AEHeader);
    hdr.fArch     = kOutputArch;

    /////////////////////////////////////////////////////////////////////////////////////////

    // COMPILATION LOOP

    /////////////////////////////////////////////////////////////////////////////////////////

    CompilerKit::Encoder64x0 asm64;

    while (std::getline(file_ptr, line)) {
      if (auto ln = asm64.CheckLine(line, argv[i]); !ln.empty()) {
        Detail::print_error(ln, argv[i]);
        continue;
      }

      try {
        asm_read_attributes(line);
        asm64.WriteLine(line, argv[i]);
      } catch (const std::exception& e) {
        if (kVerbose) {
          std::string what = e.what();
          Detail::print_warning("exit because of: " + what, "CompilerKit");
        }

        std::filesystem::remove(object_output);
        goto asm_fail_exit;
      }
    }

    if (!kOutputAsBinary) {
      if (kVerbose) {
        kStdOut << "Assembler64x0: Writing object file...\n";
      }

      // this is the final step, write everything to the file.

      auto pos = file_ptr_out.tellp();

      hdr.fCount = kRecords.size() + kUndefinedSymbols.size();

      file_ptr_out << hdr;

      if (kRecords.empty()) {
        kStdErr << "Assembler64x0: At least one record is needed to write an object "
                   "file.\nAssembler64x0: Make one using `public_segment .code64 foo_bar`.\n";

        std::filesystem::remove(object_output);
        return 1;
      }

      kRecords[kRecords.size() - 1].fSize = kBytes.size();

      std::size_t record_count = 0UL;

      for (auto& rec : kRecords) {
        if (kVerbose) kStdOut << "Assembler64x0: Wrote record " << rec.fName << " to file...\n";

        rec.fFlags |= CompilerKit::kKindRelocationAtRuntime;
        rec.fOffset = record_count;
        ++record_count;

        file_ptr_out << rec;
      }

      // increment once again, so that we won't lie about the kUndefinedSymbols.
      ++record_count;

      for (auto& sym : kUndefinedSymbols) {
        CompilerKit::AERecordHeader _record_hdr{0};

        if (kVerbose) kStdOut << "Assembler64x0: Wrote symbol " << sym << " to file...\n";

        _record_hdr.fKind   = kAENullType;
        _record_hdr.fSize   = sym.size();
        _record_hdr.fOffset = record_count;

        ++record_count;

        memset(_record_hdr.fPad, kAENullType, kAEPad);
        memcpy(_record_hdr.fName, sym.c_str(), sym.size());

        file_ptr_out << _record_hdr;

        ++kCounter;
      }

      auto pos_end = file_ptr_out.tellp();

      file_ptr_out.seekp(pos);

      hdr.fStartCode = pos_end;
      hdr.fCodeSize  = kBytes.size();

      file_ptr_out << hdr;

      file_ptr_out.seekp(pos_end);
    } else {
      if (kVerbose) {
        kStdOut << "Assembler64x0: Write raw binary...\n";
      }
    }

    // byte from byte, we write this.
    for (auto& byte : kBytes) {
      file_ptr_out.write(reinterpret_cast<const char*>(&byte), sizeof(byte));
    }

    if (kVerbose) kStdOut << "Assembler64x0: Wrote file with program in it.\n";

    file_ptr_out.flush();
    file_ptr_out.close();

    if (kVerbose) kStdOut << "Assembler64x0: Exit succeeded.\n";

    return 0;
  }

asm_fail_exit:

  if (kVerbose) kStdOut << "Assembler64x0: Exit failed.\n";

  return 1;
}

/////////////////////////////////////////////////////////////////////////////////////////

// @brief Check for attributes
// returns true if any was found.

/////////////////////////////////////////////////////////////////////////////////////////

static bool asm_read_attributes(std::string line) {
  // extern_segment is the opposite of public_segment, it signals to the ld
  // that we need this symbol.
  if (CompilerKit::find_word(line, "extern_segment")) {
    if (kOutputAsBinary) {
      Detail::print_error("Invalid extern_segment directive in flat binary mode.", "CompilerKit");
      throw std::runtime_error("invalid_extern_segment_bin");
    }

    auto name = line.substr(line.find("extern_segment") + strlen("extern_segment"));

    /// sanity check to avoid stupid linker errors.
    if (name.size() == 0) {
      Detail::print_error("Invalid extern_segment", "power-as");
      throw std::runtime_error("invalid_extern_segment");
    }

    std::string result = std::to_string(name.size());
    result += kUndefinedSymbol;

    // mangle this
    for (char& j : name) {
      if (j == ' ' || j == ',') j = '$';
    }

    result += name;

    if (name.find(".code64") != std::string::npos) {
      // data is treated as code.
      kCurrentRecord.fKind = CompilerKit::kPefCode;
    } else if (name.find(".data64") != std::string::npos) {
      // no code will be executed from here.
      kCurrentRecord.fKind = CompilerKit::kPefData;
    } else if (name.find(".zero64") != std::string::npos) {
      // this is a bss section.
      kCurrentRecord.fKind = CompilerKit::kPefZero;
    }

    // this is a special case for the start stub.
    // we want this so that ld can find it.

    if (name == kPefStart) {
      kCurrentRecord.fKind = CompilerKit::kPefCode;
    }

    // now we can tell the code size of the previous kCurrentRecord.

    if (!kRecords.empty()) kRecords[kRecords.size() - 1].fSize = kBytes.size();

    memset(kCurrentRecord.fName, 0, kAESymbolLen);
    memcpy(kCurrentRecord.fName, result.c_str(), result.size());

    ++kCounter;

    memset(kCurrentRecord.fPad, kAENullType, kAEPad);

    kRecords.emplace_back(kCurrentRecord);

    return true;
  }
  // public_segment is a special keyword used by Assembler64x0 to tell the AE output stage to
  // mark this section as a header. it currently supports .code64, .data64.,
  // .zero64
  else if (CompilerKit::find_word(line, "public_segment")) {
    if (kOutputAsBinary) {
      Detail::print_error("Invalid public_segment directive in flat binary mode.", "CompilerKit");
      throw std::runtime_error("invalid_public_segment_bin");
    }

    auto name = line.substr(line.find("public_segment") + strlen("public_segment"));

    std::string name_copy = name;

    for (char& j : name) {
      if (j == ' ') j = '$';
    }

    if (name.find(".code64") != std::string::npos) {
      // data is treated as code.

      name_copy.erase(name_copy.find(".code64"), strlen(".code64"));
      kCurrentRecord.fKind = CompilerKit::kPefCode;
    } else if (name.find(".data64") != std::string::npos) {
      // no code will be executed from here.

      name_copy.erase(name_copy.find(".data64"), strlen(".data64"));
      kCurrentRecord.fKind = CompilerKit::kPefData;
    } else if (name.find(".zero64") != std::string::npos) {
      // this is a bss section.

      name_copy.erase(name_copy.find(".zero64"), strlen(".zero64"));
      kCurrentRecord.fKind = CompilerKit::kPefZero;
    }

    // this is a special case for the start stub.
    // we want this so that ld can find it.

    if (name == kPefStart) {
      kCurrentRecord.fKind = CompilerKit::kPefCode;
    }

    while (name_copy.find(" ") != std::string::npos) name_copy.erase(name_copy.find(" "), 1);

    kOriginLabel.push_back(std::make_pair(name_copy, kOrigin));
    ++kOrigin;

    // now we can tell the code size of the previous kCurrentRecord.

    if (!kRecords.empty()) kRecords[kRecords.size() - 1].fSize = kBytes.size();

    memset(kCurrentRecord.fName, 0, kAESymbolLen);
    memcpy(kCurrentRecord.fName, name.c_str(), name.size());

    ++kCounter;

    memset(kCurrentRecord.fPad, kAENullType, kAEPad);

    kRecords.emplace_back(kCurrentRecord);

    return true;
  }

  return false;
}

// \brief algorithms and helpers.

namespace Detail::algorithm {
// \brief authorize a brief set of characters.
static inline bool is_not_alnum_space(char c) {
  return !(isalpha(c) || isdigit(c) || (c == ' ') || (c == '\t') || (c == ',') || (c == '(') ||
           (c == ')') || (c == '"') || (c == '\'') || (c == '[') || (c == ']') || (c == '+') ||
           (c == '_') || (c == ':') || (c == '@') || (c == '.'));
}

bool is_valid_64x0(std::string str) {
  return std::find_if(str.begin(), str.end(), is_not_alnum_space) == str.end();
}
}  // namespace Detail::algorithm

/////////////////////////////////////////////////////////////////////////////////////////

// @brief Check for line (syntax check)

/////////////////////////////////////////////////////////////////////////////////////////

std::string CompilerKit::Encoder64x0::CheckLine(std::string line, std::string file) {
  std::string err_str;

  if (line.empty() || CompilerKit::find_word(line, "extern_segment") ||
      CompilerKit::find_word(line, "public_segment") || line.find('#') != std::string::npos ||
      CompilerKit::find_word(line, ";")) {
    if (line.find('#') != std::string::npos) {
      line.erase(line.find('#'));
    } else if (line.find(';') != std::string::npos) {
      line.erase(line.find(';'));
    } else {
      // now check the line for validity
      if (!Detail::algorithm::is_valid_64x0(line)) {
        err_str = "Line contains non alphanumeric characters.\nhere -> ";
        err_str += line;
      }
    }

    return err_str;
  }

  if (!Detail::algorithm::is_valid_64x0(line)) {
    err_str = "Line contains non alphanumeric characters.\nhere -> ";
    err_str += line;

    return err_str;
  }

  // check for a valid instruction format.

  if (line.find(',') != std::string::npos) {
    if (line.find(',') + 1 == line.size()) {
      err_str += "\nInstruction lacks right register, here -> ";
      err_str += line.substr(line.find(','));

      return err_str;
    } else {
      bool nothing_on_right = true;

      if (line.find(',') + 1 > line.size()) {
        err_str += "\nInstruction not complete, here -> ";
        err_str += line;

        return err_str;
      }

      auto substr = line.substr(line.find(',') + 1);

      for (auto& ch : substr) {
        if (ch != ' ' && ch != '\t') {
          nothing_on_right = false;
        }
      }

      // this means we found nothing after that ',' .
      if (nothing_on_right) {
        err_str += "\nInstruction not complete, here -> ";
        err_str += line;

        return err_str;
      }
    }
  }

  // these do take an argument.
  std::vector<std::string> operands_inst = {"stw", "ldw", "lda", "sta"};

  // these don't.
  std::vector<std::string> filter_inst = {"jlr", "jrl", "int"};

  for (auto& opcode64x0 : kOpcodes64x0) {
    if (line.find(opcode64x0.fName) != std::string::npos) {
      if (opcode64x0.fFunct7 == kAsmNoArgs) return err_str;

      for (auto& op : operands_inst) {
        // if only the instruction was found.
        if (line == op) {
          err_str += "\nMalformed ";
          err_str += op;
          err_str += " instruction, here -> ";
          err_str += line;
        }
      }

      // if it is like that -> addr1, 0x0
      if (auto it = std::find(filter_inst.begin(), filter_inst.end(), opcode64x0.fName);
          it == filter_inst.cend()) {
        if (CompilerKit::find_word(line, opcode64x0.fName)) {
          if (!isspace(line[line.find(opcode64x0.fName) + strlen(opcode64x0.fName)])) {
            err_str += "\nMissing space between ";
            err_str += opcode64x0.fName;
            err_str += " and operands.\nhere -> ";
            err_str += line;
          }
        }
      }

      return err_str;
    }
  }

  err_str += "Unrecognized instruction: " + line;

  return err_str;
}

bool CompilerKit::Encoder64x0::WriteNumber(const std::size_t& pos, std::string& jump_label) {
  if (!isdigit(jump_label[pos])) return false;

  switch (jump_label[pos + 1]) {
    case 'x': {
      if (auto res = strtol(jump_label.substr(pos + 2).c_str(), nullptr, 16); !res) {
        if (errno != 0) {
          Detail::print_error("invalid hex number: " + jump_label, "CompilerKit");
          throw std::runtime_error("invalid_hex_number");
        }
      }

      CompilerKit::NumberCast64 num(strtol(jump_label.substr(pos + 2).c_str(), nullptr, 16));

      for (char& i : num.number) {
        kBytes.push_back(i);
      }

      if (kVerbose) {
        kStdOut << "Assembler64x0: found a base 16 number here: " << jump_label.substr(pos) << "\n";
      }

      return true;
    }
    case 'b': {
      if (auto res = strtol(jump_label.substr(pos + 2).c_str(), nullptr, 2); !res) {
        if (errno != 0) {
          Detail::print_error("invalid binary number: " + jump_label, "CompilerKit");
          throw std::runtime_error("invalid_bin");
        }
      }

      CompilerKit::NumberCast64 num(strtol(jump_label.substr(pos + 2).c_str(), nullptr, 2));

      if (kVerbose) {
        kStdOut << "Assembler64x0: found a base 2 number here: " << jump_label.substr(pos) << "\n";
      }

      for (char& i : num.number) {
        kBytes.push_back(i);
      }

      return true;
    }
    case 'o': {
      if (auto res = strtol(jump_label.substr(pos + 2).c_str(), nullptr, 7); !res) {
        if (errno != 0) {
          Detail::print_error("invalid octal number: " + jump_label, "CompilerKit");
          throw std::runtime_error("invalid_octal");
        }
      }

      CompilerKit::NumberCast64 num(strtol(jump_label.substr(pos + 2).c_str(), nullptr, 7));

      if (kVerbose) {
        kStdOut << "Assembler64x0: found a base 8 number here: " << jump_label.substr(pos) << "\n";
      }

      for (char& i : num.number) {
        kBytes.push_back(i);
      }

      return true;
    }
    default: {
      break;
    }
  }

  /* check for errno and stuff like that */
  if (auto res = strtol(jump_label.substr(pos).c_str(), nullptr, 10); !res) {
    if (errno != 0) {
      return false;
    }
  }

  CompilerKit::NumberCast64 num(strtol(jump_label.substr(pos).c_str(), nullptr, 10));

  for (char& i : num.number) {
    kBytes.push_back(i);
  }

  if (kVerbose) {
    kStdOut << "Assembler64x0: found a base 10 number here: " << jump_label.substr(pos) << "\n";
  }

  return true;
}

/////////////////////////////////////////////////////////////////////////////////////////

// @brief Read and write an instruction to the output array.

/////////////////////////////////////////////////////////////////////////////////////////

bool CompilerKit::Encoder64x0::WriteLine(std::string line, std::string file) {
  if (CompilerKit::find_word(line, "public_segment ")) return true;

  for (auto& opcode64x0 : kOpcodes64x0) {
    // strict check here
    if (CompilerKit::find_word(line, opcode64x0.fName) && Detail::algorithm::is_valid_64x0(line)) {
      std::string name(opcode64x0.fName);
      std::string jump_label, cpy_jump_label;

      kBytes.emplace_back(opcode64x0.fOpcode);
      kBytes.emplace_back(opcode64x0.fFunct3);
      kBytes.emplace_back(opcode64x0.fFunct7);

      // check funct7 type.
      switch (opcode64x0.fFunct7) {
        // reg to reg means register to register transfer operation.
        case kAsmRegToReg:
        case kAsmImmediate: {
          // \brief how many registers we found.
          std::size_t found_some = 0UL;

          for (size_t line_index = 0UL; line_index < line.size(); line_index++) {
            if (line[line_index] == kAsmRegisterPrefix[0] && isdigit(line[line_index + 1])) {
              std::string register_syntax = kAsmRegisterPrefix;
              register_syntax += line[line_index + 1];

              if (isdigit(line[line_index + 2])) register_syntax += line[line_index + 2];

              std::string reg_str;
              reg_str += line[line_index + 1];

              if (isdigit(line[line_index + 2])) reg_str += line[line_index + 2];

              // it ranges from r0 to r19
              // something like r190 doesn't exist in the instruction set.
              if (kOutputArch == CompilerKit::kPefArch64000) {
                if (isdigit(line[line_index + 3]) && isdigit(line[line_index + 2])) {
                  reg_str += line[line_index + 3];
                  Detail::print_error("invalid register index, r" + reg_str +
                                          "\nnote: The 64x0 accepts registers from r0 to r20.",
                                      file);
                  throw std::runtime_error("invalid_register_index");
                }
              }

              // finally cast to a size_t
              std::size_t reg_index = strtol(reg_str.c_str(), nullptr, 10);

              if (reg_index > kAsmRegisterLimit) {
                Detail::print_error("invalid register index, r" + reg_str, file);
                throw std::runtime_error("invalid_register_index");
              }

              kBytes.emplace_back(reg_index);
              ++found_some;

              if (kVerbose) {
                kStdOut << "Assembler64x0: Register found: " << register_syntax << "\n";
                kStdOut << "Assembler64x0: Register amount in instruction: " << found_some << "\n";
              }
            }
          }

          // we're not in immediate addressing, reg to reg.
          if (opcode64x0.fFunct7 != kAsmImmediate) {
            // remember! register to register!
            if (found_some == 1) {
              Detail::print_error(
                  "Too few registers.\ntip: each Assembler64x0 register "
                  "starts with 'r'.\nline: " +
                      line,
                  file);
              throw std::runtime_error("not_a_register");
            }
          }

          if (found_some < 1 && name != "ldw" && name != "lda" && name != "stw") {
            Detail::print_error("invalid combination of opcode and registers.\nline: " + line,
                                file);
            throw std::runtime_error("invalid_comb_op_reg");
          } else if (found_some == 1 && name == "add") {
            Detail::print_error("invalid combination of opcode and registers.\nline: " + line,
                                file);
            throw std::runtime_error("invalid_comb_op_reg");
          } else if (found_some == 1 && name == "sub") {
            Detail::print_error("invalid combination of opcode and registers.\nline: " + line,
                                file);
            throw std::runtime_error("invalid_comb_op_reg");
          }

          if (found_some > 0 && name == "pop") {
            Detail::print_error(
                "invalid combination for opcode 'pop'.\ntip: it expects "
                "nothing.\nline: " +
                    line,
                file);
            throw std::runtime_error("invalid_comb_op_pop");
          }
        }
        default:
          break;
      }

      // try to fetch a number from the name
      if (name == "stw" || name == "ldw" || name == "lda" || name == "sta") {
        auto where_string = name;

        // if we load something, we'd need it's symbol/literal
        if (name == "stw" || name == "sta" || name == "ldw" || name == "lda" || name == "sta")
          where_string = ",";

        jump_label = line;

        auto found_sym = false;

        while (jump_label.find(where_string) != std::string::npos) {
          jump_label = jump_label.substr(jump_label.find(where_string) + where_string.size());

          while (jump_label.find(" ") != std::string::npos) {
            jump_label.erase(jump_label.find(" "), 1);
          }

          if (jump_label[0] != kAsmRegisterPrefix[0] && !isdigit(jump_label[1])) {
            if (found_sym) {
              Detail::print_error(
                  "invalid combination of opcode and operands.\nhere -> " + jump_label, file);
              throw std::runtime_error("invalid_comb_op_ops");
            } else {
              // death trap installed.
              found_sym = true;
            }
          }
        }

        cpy_jump_label = jump_label;

        // replace any spaces with $
        if (jump_label[0] == ' ') {
          while (jump_label.find(' ') != std::string::npos) {
            if (isalnum(jump_label[0]) || isdigit(jump_label[0])) break;

            jump_label.erase(jump_label.find(' '), 1);
          }
        }

        if (!this->WriteNumber(0, jump_label)) {
          // sta expects this: sta 0x000000, r0
          if (name == "sta") {
            Detail::print_error("invalid combination of opcode and operands.\nHere ->" + line,
                                file);
            throw std::runtime_error("invalid_comb_op_ops");
          }
        } else {
          if (name == "sta" && cpy_jump_label.find("extern_segment ") != std::string::npos) {
            Detail::print_error("invalid usage extern_segment on 'sta', here: " + line, file);
            throw std::runtime_error("invalid_sta_usage");
          }
        }

        goto asm_write_label;
      }

      // This is the case where we jump to a label, it is also used as a goto.
      if (name == "lda" || name == "sta") {
      asm_write_label:
        if (cpy_jump_label.find('\n') != std::string::npos)
          cpy_jump_label.erase(cpy_jump_label.find('\n'), 1);

        if (cpy_jump_label.find("extern_segment") != std::string::npos) {
          cpy_jump_label.erase(cpy_jump_label.find("extern_segment"), strlen("extern_segment"));

          if (name == "sta") {
            Detail::print_error("extern_segment is not allowed on a sta operation.", file);
            throw std::runtime_error("extern_segment_sta_op");
          } else {
            goto asm_end_label_cpy;
          }
        }

        if (name == "lda" || name == "sta") {
          for (auto& label : kOriginLabel) {
            if (cpy_jump_label == label.first) {
              if (kVerbose) {
                kStdOut << "Assembler64x0: Replace label " << cpy_jump_label
                        << " to address: " << label.second << std::endl;
              }

              CompilerKit::NumberCast64 num(label.second);

              for (auto& num : num.number) {
                kBytes.push_back(num);
              }

              goto asm_end_label_cpy;
            }
          }

          if (cpy_jump_label[0] == '0') {
            switch (cpy_jump_label[1]) {
              case 'x':
              case 'o':
              case 'b':
                if (this->WriteNumber(0, cpy_jump_label)) goto asm_end_label_cpy;

                break;
              default:
                break;
            }

            if (isdigit(cpy_jump_label[0])) {
              if (this->WriteNumber(0, cpy_jump_label)) goto asm_end_label_cpy;

              break;
            }
          }
        }

        if (cpy_jump_label.size() < 1) {
          Detail::print_error("label is empty, can't jump on it.", file);
          throw std::runtime_error("label_empty");
        }

        /// don't go any further if:
        /// load word (ldw) or store word. (stw)

        if (name == "ldw" || name == "stw") break;

        auto mld_reloc_str = std::to_string(cpy_jump_label.size());
        mld_reloc_str += kUndefinedSymbol;
        mld_reloc_str += cpy_jump_label;

        bool ignore_back_slash = false;

        for (auto& reloc_chr : mld_reloc_str) {
          if (reloc_chr == '\\') {
            ignore_back_slash = true;
            continue;
          }

          if (ignore_back_slash) {
            ignore_back_slash = false;
            continue;
          }

          kBytes.push_back(reloc_chr);
        }

        kBytes.push_back('\0');
        goto asm_end_label_cpy;
      }

    asm_end_label_cpy:
      kOrigin += k64x0IPAlignment;

      break;
    }
  }

  return true;
}

// Last rev 13-1-24