lex.h

#include <string>

#include <signal.h>

using namespace std;

#define CRASH_NOW()  raise(SIGSEGV); 

#define EOT -9999

#define CHAR_AT(pos,line_no) str_line[line_no].at(pos)

#define SPACE_CHECK(pos) CHAR_AT(pos, line_no) == ' ' ||  \

                         CHAR_AT(pos, line_no) == '\n' || \

                         CHAR_AT(pos, line_no) == '\v' || \

                         CHAR_AT(pos, line_no) == '\t'

#define NULL_CHECK(pos)  str_line[line_no].length() <= pos

#define NL_CHECK(pos)     if (NULL_CHECK(pos))    \

                          {                  \

                             pos = 0;         \

                             line_no++;       \

                          }

#define ALPHA_NUM_CHECK(pos) ((CHAR_AT(pos, line_no) >= 'a' && CHAR_AT(pos, line_no) <= 'z') || (CHAR_AT(pos, line_no) >= 'A' && CHAR_AT(pos, line_no) <= 'Z') || (CHAR_AT(pos, line_no) >= '0' && CHAR_AT(pos, line_no) <= '9'))

/* Macro Values for Tokens */

#define ELIPPSIS 0x1000

#define ADD_ASSIGN 0x1001

#define INC_OP 0x1002

#define SUB_ASSIGN 0x1003

#define DEC_OP 0x1004

#define DIV_ASSIGN 0x1005

#define MUL_ASSIGN 0x1006

#define MOD_ASSIGN 0x1007

#define AND_ASSIGN 0x1008

#define XOR_ASSIGN 0x1009

#define OR_ASSIGN 0x1010

#define NOT_ASSIGN 0x1011

#define RIGHT_OP 0x1012

#define LEFT_OP 0x1013

#define ID 0x1014

#define STROBJ 0x1015

#define INT_CONST 0x1016

#define F_CONST 0x1017

/* Keyword token */

#define AUTO 0

#define BREAK 1

#define CASE 2

#define CHAR 3

#define CONST 4

#define CONTINUE 5

#define DEFAULT 6

#define DO 7

#define DOUBLE 8

#define ELSE 9

#define ENUM 10

#define EXTERN 11

#define FLOAT 12

#define FOR 13

#define GOTO 14

#define IF 15

#define INT 16

#define LONG 17

#define REGISTER 18

#define RETURN 19

#define SHORT 20

#define SIGNED 21

#define SIZEOF 22

#define STATIC 23

#define STRUCT 24

#define SWITCH 25

#define TYPEDEF 26

#define UNION 27

#define UNSIGNED 28

#define VOID 29

#define VOLATILE 30

#define WHILE 31

int keyword_check(string str, bool &is_keyword);

int getToken(string *str_line, int max);

#define NO_PREPROCESSOR 1

#ifdef NO_PREPROCESSOR

bool is_first(string str_line, char c);

#define is_prep()   if(is_first(str_line[line_no], '#')) \

                    {                                    \

                           pos= 0;                       \

                           line_no++;                    \

                    }                                    \

#endif