Flex 替换输入的字符串

#include <iostream>
#include "lexer.h"

#define yylex aaslex
#define yy_scan_string aas_scan_string
#define yy_delete_buffer aas_delete_buffer
extern char* yylex(std::string& res);

int main()
{
  std::string src = 
    "define(def1, 1 + 2)
"
    "define(def2,eax,1)
"
    "define(def3,0x22222)
"
    "define(def4,01 def3 02)
"
    "define(def5)
"

    "def3:
"
    "db 90 90 #90 def4 // db 指令 
"
    "mov def2

"
    "lea	eax [def1]
"
    ;

  YY_BUFFER_STATE state = yy_scan_string(src.data());
  std::string res;
  yylex(res);
  yy_delete_buffer(state);
  std::cout << res << "
";
}

lexer.l:

%option noyywrap noline
%option prefix="aas"
%option header-file="lexer.h"

%{
#include <iostream>
#include <string>
#include <map>

#define YY_DECL char * yylex (std::string& res)
#define O(v) res += v
#define GET_DEFINE (defineMap.count(yytext) ? defineMap[yytext] : yytext)

// save dafines
std::string cur_define_key;
std::string cur_define_val;
std::map<std::string, std::string> defineMap;
%}


ID  (?i:[a-z][a-z0-9]*)

%x define define_val
%%

<*>"//".* { /* eat comment */ }

"define(" { BEGIN(define); }
<define>{ID}  { cur_define_key = yytext;  }
<define>","   { BEGIN(define_val); cur_define_val = ""; }
<define_val>[ 	]+ { cur_define_val += yytext; }
<define_val>{ID} { cur_define_val += GET_DEFINE;  }
<define_val>[^)
] { cur_define_val += yytext; }
<define_val>")"  { /* define end */ defineMap[cur_define_key] = cur_define_val; BEGIN(0); }
<define>")"  { printf("Error: 必须要有一个参数
"); BEGIN(0); }

{ID} { O( GET_DEFINE );  }

 { O(yytext); }
. { O(yytext); }

<<EOF>> { 
  std::cout << "===================================" << "
";
  for (auto i = defineMap.begin(); i != defineMap.end(); i++)
  {
    printf("key:%s, value:%s
", i->first.data(), i->second.data());
  }
  std::cout << "===================================" << "
";
  defineMap.clear();

  return NULL; 
}

%%

print:

Error: 必须要有一个参数
===================================
key:def1, value: 1 + 2
key:def2, value:eax,1
key:def3, value:0x22222
key:def4, value:01 0x22222 02
===================================





0x22222:
db 90 90 #90 01 0x22222 02
mov eax,1

lea     eax [ 1 + 2]