编译基本汇编程序时链接错误

我正在尝试创建一个将使用特定计算机类型运行的特殊汇编程序。我试图编译该程序，但是有一个链接器错误：

/usr/bin/ld：lexer.o：in Function`Lexer :: Lex（std :: __ __ cxx11 :: basic_string，std :: allocator>: salcator>：aeltocator>）'：

lexer.cpp :(。text 0x2ee）：未定义的引用`lexer :: isspecial（char）'

collect2：错误：LD返回1退出状态

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我有3个主要文件：lexer.h，lexer.cpp，sasm.cpp。这是代码。

lexer.h：

#ifndef LEXER_H
  #define LEXER_H
  #include <iostream>
  #include <vector>
  // type definitions
  typedef uint8_t byte;
  typedef std::vector<std::string> strings;
  enum State : byte {
    START,
    READCHAR,
    READBLOCK,
    SKIP,
    DUMP,
    COMMENT,
    END
  };
  // Instructions definitions
  #define ADD 0x40000001
  #define SUB 0x40000002
  #define TIME 0x40000003
  #define DIVIDE 0x40000004
  #define HALT 0x40000000
  class Lexer {
  private:
    bool isSpace(char c);
    bool isSpecial(char c);
    bool isGroup(char c);
    char end_char, beg_char;
  public:
    strings lex(std::string s);
  };
#endif

lexer.cpp：

#include "lexer.h"
strings Lexer::lex(std::string s) {
  strings strLst;
  char lexEme[256];
  int i = 0;
  int j = 0;
  State state = START;
  int done = 0;
  int len = s.length();
  int balance = 0;
  while (i < len) {
    switch (state) {
      case START:
        if (isSpace(s[i])) {
          state = SKIP;
        } else if (isGroup(s[i])) {
          if (s[i] == '"') {
            lexEme[j] = s[i];
            j++;
            i++;
          }
          state = READBLOCK;
        } else if (s[i] == '/' && s[i + 1] == '/') {
          i += 2;
          state = COMMENT;
        } else {
          state = READCHAR;
        }
        break;
      case READCHAR:
        if (isSpace(s[i])) {
          state = DUMP;
        } else if (s[i] == '') {
          i += 2;
        } else if (isGroup(s[i])) {
          if (s[i] == '"') {
            lexEme[j] = s[i];
            j++;
            i++;
          }
          state = READBLOCK;
        } else if (isSpecial(s[i])) {
          if (j == 0) {
            lexEme[j] = s[i];
            j++;
            i++;
          }
          state = DUMP;
        } else if (s[i] == '/' && s[i + 1] == '/') {
          i += 2;
          state = COMMENT;
        } else {
          lexEme[j] = s[i];
          j++;
          i++;
        }
        break;
      case READBLOCK:
        if (s[i] == beg_char && s[i] != '"') {
          balance++;
          lexEme[j] = s[i];
          j++;
          i++;
        } else if (s[i] == end_char) {
          balance--;
          lexEme[j] = s[i];
          j++;
          i++;
          if (balance <= 0) {
            state = DUMP;
          }
        } else if (end_char == '"' && s[i] == '') {
          // TODO: fix this to actually record the chars
          i += 2;
        } else {
          lexEme[j] = s[i];
          j++;
          i++;
        }
        break;
      case SKIP:
        if (isSpace(s[i])) {
          i++;
        } else {
          state = READCHAR;
        }
        break;
      case DUMP:
        if (j < 0) {
          lexEme[j] = 0;
          strLst.push_back(lexEme);
          j = 0;
        }
        state = START;
        break;
      case COMMENT:
        if (s[i] != 'n') {
          i++;
        } else {
          state = READCHAR;
        }
        break;
      case END:
        i = len;
        break;
    }
  }
  if (j > 0) {
    lexEme[j] = 0;
    strLst.push_back(lexEme);
  }
  return strLst;
}
// This function allows us what a space is
bool Lexer::isSpace(char c) {
  switch (c) {
    case 'n':
    case 'r':
    case 't':
    case 'v':
    case ' ':
    case 'f':
      return true;
    default:
      return false;
  }
}
bool Lexer::isGroup(char c) {
  beg_char = c;
  switch (c) {
    case '"':
      end_char = '"';
      return true;
    case '(' :
      end_char = ')';
      return true;
    case ')':
      return true;
    default:
      return false;
  }
}
bool isSpecial(char c) {
  switch (c) {
    case '[':
    case ']':
      return true;
    default:
      return false;
  }
}

sasm.cpp：

#include <fstream>
#include "lexer.h"
typedef uint32_t i32;
using namespace std;
vector<i32> compile(strings s);
bool isInteger(string s);
bool isPrimitive(string s);
i32 mapToNumber(string s);
int main (int argc, char* argv[]) {
  // Check for input errors
  if (argc != 2) {
    cerr << "Usage: " << argv[0] << " <sasm-file>" << endl;
    exit(1);
  }
  // Read input file
  ifstream infile;
  infile.open(argv[1]);
  if (!infile.is_open()) {
    cerr << argv[1] << ": file can't be found" << endl;
    exit(1);
  }
  string line;
  string contents;
  while (getline(infile, line)) {
    contents += line + "n";
  }
  infile.close();
  // Parse infile
  Lexer lexer;
  strings lexEmes = lexer.lex(contents);
  // Compile binary
  vector<i32> instructions = compile(lexEmes);
  // Write instructions to file
  ofstream ofile;
  ofile.open("out.bin", ios::binary);
  for (i32 i = 0; i < instructions.size(); i++) {
    ofile.write(reinterpret_cast<char*>(&instructions[i]), sizeof(i32));
  }
  ofile.close();
  return 0;
}
vector<i32> compile(strings s) {
  vector<i32> instructions;
  for (i32 i = 0; i < s.size(); i++) {
    if (isInteger(s[i])) {
      instructions.push_back(stoi(s[i]));
    } else {
      i32 instruction = mapToNumber(s[i]);
      if (instruction != -1) {
        instructions.push_back(instruction);
      } else {
        cerr << "33[1;31m" << s[i] << "33[0m Invalid instruction" << std::endl;
      }
    }
  }
  return instructions;
}
bool isInteger(string s) {
  for (i32 i = 0; i < s.length(); i++) {
    if (!isdigit(s[i])) {
      return false;
    }
  }
  return true;
}
i32 mapToNumber(string s) {
  if (s == "+") {
    return ADD;
  } else if (s == "-") {
    return SUB;
  } else if (s == "*") {
    return TIME;
  } else if (s == "/") {
    return DIVIDE;
  }
  return -1; // Invalid instruction
}

感谢您的回答。