📄 lex.cpp
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#include "stdafx.h"
#include "common.h"
#include "lex.h"#include <io.h>
#include <malloc.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
void local_init();void local_end();
static int _stdcall act_identity(char&c);static int _stdcall act_comment2(char&c);static int _stdcall act_string(char&c);static int _stdcall act_comment1(char&c);static int _stdcall act_chinese(char&c);static int _stdcall act_number(char&c,int state);static void *yy_flex_alloc ( unsigned int );static void *yy_flex_realloc ( void *, unsigned int );static void yy_flex_free ( void * );
static TUPLE result_tuple;static int yy_linenum=1;static int yy_stringpos;static int yy_init = 1;
#ifdef YY_USER_INIT#undef YY_USER_INIT#endif
#define YY_USER_INIT local_init()#ifdef YY_USER_END#undef YY_USER_END#endif
#define YY_USER_END local_end()
struct yy_buffer_state{ FILE *yy_input_file; char *yy_ch_buf;//输入缓冲区
char *yy_buf_pos;//输入缓冲区的当前位置 unsigned int yy_buf_size;//输入缓冲区的大小,不包括结束标志 int yy_n_chars;//输入缓冲区中字符数目,不包括结束标志 int yy_is_our_buffer;//是否拥有这个缓冲区,同智能指针的解决方案 int yy_is_interactive;//是否是交互式的输入源,如果是控制台则yy_input_file为空 int yy_at_bol;//是否在行开始 int yy_fill_buffer;//如果缓冲区数据用完,是否读入新的数据,如果为0的话表示文件结束 int yy_buffer_status;//缓冲区状态,下面有定义#define YY_BUFFER_NEW 0#define YY_BUFFER_NORMAL 1#define YY_BUFFER_EOF_PENDING 2};
typedef struct yy_buffer_state *YY_BUFFER_STATE;#define YY_END_OF_BUFFER_CHAR 0//结束标志#define YY_BUF_SIZE 1024//定义缓冲区大小#define YY_READ_BUF_SIZE 1024
//当前缓冲区和它的窗口变量
static YY_BUFFER_STATE yy_current_buffer = 0;#define YY_CURRENT_BUFFER yy_current_bufferstatic char yy_hold_char;static int yy_n_chars;#define YY_MORE_ADJ 0static char *yytext;static char *yy_c_buf_p = (char *) 0;
void yy_load_buffer_state( void ){ yy_n_chars = yy_current_buffer->yy_n_chars; yytext = yy_c_buf_p = yy_current_buffer->yy_buf_pos; yyin = yy_current_buffer->yy_input_file; yy_hold_char = *yy_c_buf_p; }
//使b中的所有数据失效,如果b为当前缓冲区则重新装载窗口变量
void yy_flush_buffer( YY_BUFFER_STATE b ){
if ( ! b )
return;
b->yy_n_chars = 0;
b->yy_ch_buf[0] = YY_END_OF_BUFFER_CHAR;
b->yy_ch_buf[1] = YY_END_OF_BUFFER_CHAR;
b->yy_buf_pos = &b->yy_ch_buf[0];
b->yy_at_bol = 1;
b->yy_buffer_status = YY_BUFFER_NEW;
if ( b == yy_current_buffer )
yy_load_buffer_state();
}
//使b无效,把file放入b中
void yy_init_buffer( YY_BUFFER_STATE b, FILE *file ){
yy_flush_buffer( b );
b->yy_input_file = file;
b->yy_fill_buffer = 1;
b->yy_is_interactive = file ? (isatty( fileno(file) ) > 0) : 0;
}
//创建一个包装好的缓冲区(file,size)
YY_BUFFER_STATE yy_create_buffer( FILE *file, int size ){
YY_BUFFER_STATE b;
b = (YY_BUFFER_STATE) yy_flex_alloc( sizeof( struct yy_buffer_state ) );
if ( ! b )
yy_fatal_error( "out of dynamic memory in yy_create_buffer()" );
b->yy_buf_size = size;
b->yy_ch_buf = (char *) yy_flex_alloc( b->yy_buf_size + 2 );
if ( ! b->yy_ch_buf )
yy_fatal_error( "out of dynamic memory in yy_create_buffer()" );
b->yy_is_our_buffer = 1;
yy_init_buffer( b, file );
return b;
}
// 释放缓冲区控制块和缓冲区
void yy_delete_buffer( YY_BUFFER_STATE b ){
if ( ! b )
return;
if ( b == yy_current_buffer )
yy_current_buffer = (YY_BUFFER_STATE) 0;
if ( b->yy_is_our_buffer )
yy_flex_free( (void *) b->yy_ch_buf );
yy_flex_free( (void *) b );
}
/*定义yy_get_next_buffer的返回结果*/
#define EOB_ACT_CONTINUE_SCAN 0
#define EOB_ACT_END_OF_FILE 1
#define EOB_ACT_LAST_MATCH 2
static int yy_get_next_buffer();//取下一个缓冲区
static int yyinput();//取下一个字符
static void yyunput( int c, register char *yy_bp );
void yyrestart( FILE *input_file );
#ifdef YY_STRING
static int myinput(char* buf, int max);
#define YY_INPUT(buf,result,max) {result = myinput(buf,max);}
#else
#define YY_INPUT(buf,result,max_size)\ if ( yy_current_buffer->yy_is_interactive )\ { \ int c = '*', n; \ for ( n = 0; n < max_size && \ (c = getc( yyin )) != EOF && c != '\n'; ++n ) \ buf[n] = (char) c; \ if ( c == '\n' ) \ buf[n++] = (char) c; \ if ( c == EOF && ferror( yyin ) ) \ yy_fatal_error( "input in flex scanner failed" ); \ result = n; \ } \ else if ( ((result = fread( buf, 1, max_size, yyin )) == 0) \ && ferror( yyin ) ) \ yy_fatal_error( "input in flex scanner failed" );#endif
//内存分配
static void *yy_flex_alloc( unsigned int size ){
return (void *) malloc( size );
}
static void *yy_flex_realloc( void *ptr, unsigned int size ){
return (void *) realloc( (char *) ptr, size );
}
static void yy_flex_free( void *ptr ){
free( ptr );
}
/* 放回数据,与下面取数据函数相反*/
static void yyunput( int c, register char *yy_bp ){
register char *yy_cp = yy_c_buf_p;
if(c==10)yy_linenum--;
*yy_cp = yy_hold_char;
if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 ){
register int number_to_move = yy_n_chars + 2;
register char *dest = &yy_current_buffer->yy_ch_buf[
yy_current_buffer->yy_buf_size + 2];
register char *source =
&yy_current_buffer->yy_ch_buf[number_to_move];
while ( source > yy_current_buffer->yy_ch_buf )
*--dest = *--source;
yy_cp += (int) (dest - source);
yy_bp += (int) (dest - source);
yy_current_buffer->yy_n_chars =
yy_n_chars = yy_current_buffer->yy_buf_size;
if ( yy_cp < yy_current_buffer->yy_ch_buf + 2 )
yy_fatal_error( "flex scanner push-back overflow" );
}
yytext = yy_bp;
yy_hold_char = c;
yy_c_buf_p = --yy_cp;
*yy_cp=0;
}
static int yyinput(){
int c;
*yy_c_buf_p = yy_hold_char;
if ( *yy_c_buf_p == YY_END_OF_BUFFER_CHAR ){
if ( yy_c_buf_p < &yy_current_buffer->yy_ch_buf[yy_n_chars] )
*yy_c_buf_p = '\0';//数据本身为0,而不是缓冲区结束
else{
int offset = yy_c_buf_p - yytext;
++yy_c_buf_p;
switch ( yy_get_next_buffer() ){//读下一个缓冲区
case EOB_ACT_LAST_MATCH:
yyrestart( yyin );
case EOB_ACT_END_OF_FILE:
return EOF;
case EOB_ACT_CONTINUE_SCAN:
yy_c_buf_p = yytext + offset;
break;
}
}
}
c = *(unsigned char *) yy_c_buf_p;
yy_hold_char = *++yy_c_buf_p;
*yy_c_buf_p = '\0'; //形成字符串yytext
if(c==10)yy_linenum++;
return c;
}
//读取下一个有效的缓冲区
static int yy_get_next_buffer(){
register char *dest = yy_current_buffer->yy_ch_buf;//源区
register char *source = yytext;//目的区
register int number_to_move, i;
int ret_val;
if ( yy_c_buf_p > &yy_current_buffer->yy_ch_buf[yy_n_chars + 1] )//如果越过了两个结束标志
yy_fatal_error("fatal flex scanner internal error--end of buffer missed" );
if ( yy_current_buffer->yy_fill_buffer == 0 ){ //文件结束
if ( yy_c_buf_p - yytext - YY_MORE_ADJ == 1 ){
return EOB_ACT_END_OF_FILE;
}else{
return EOB_ACT_LAST_MATCH;
}
}
/* Try to read more data. */
/*将yytext到yy_c_buf_p处的字符拷贝到缓冲区头部*/
number_to_move = (int) (yy_c_buf_p - yytext) - 1;
for ( i = 0; i < number_to_move; ++i )
*(dest++) = *(source++);
if ( yy_current_buffer->yy_buffer_status == YY_BUFFER_EOF_PENDING )
yy_current_buffer->yy_n_chars = yy_n_chars = 0;
else{
int num_to_read =
yy_current_buffer->yy_buf_size - number_to_move - 1;
while ( num_to_read <= 0 ){ /* Not enough room in the buffer - grow it. */
/* just a shorter name for the current buffer */
YY_BUFFER_STATE b = yy_current_buffer;
int yy_c_buf_p_offset =
(int) (yy_c_buf_p - b->yy_ch_buf);
if ( b->yy_is_our_buffer ){
int new_size = b->yy_buf_size * 2;
if ( new_size <= 0 )
b->yy_buf_size += b->yy_buf_size / 8;
else
b->yy_buf_size *= 2;
b->yy_ch_buf = (char *)
/* Include room in for 2 EOB chars. */
yy_flex_realloc( (void *) b->yy_ch_buf,
b->yy_buf_size + 2 );
}else
/* Can't grow it, we don't own it. */
b->yy_ch_buf = 0;
if ( ! b->yy_ch_buf )
yy_fatal_error("fatal error - scanner input buffer overflow" );
yy_c_buf_p = &b->yy_ch_buf[yy_c_buf_p_offset];
num_to_read = yy_current_buffer->yy_buf_size -
number_to_move - 1;
}
if ( num_to_read > YY_READ_BUF_SIZE )
num_to_read = YY_READ_BUF_SIZE;
/*读入更多的字符,yy_n_chars为实践读入的字符数*/
YY_INPUT( (&yy_current_buffer->yy_ch_buf[number_to_move]),
yy_n_chars, num_to_read );
yy_current_buffer->yy_n_chars = yy_n_chars;
}
if ( yy_n_chars == 0 ){
if ( number_to_move == YY_MORE_ADJ ){
ret_val = EOB_ACT_END_OF_FILE;
yyrestart( yyin );
}else{
ret_val = EOB_ACT_LAST_MATCH;
yy_current_buffer->yy_buffer_status =
YY_BUFFER_EOF_PENDING;
}
}else
ret_val = EOB_ACT_CONTINUE_SCAN;
yy_n_chars += number_to_move;
yy_current_buffer->yy_ch_buf[yy_n_chars] = YY_END_OF_BUFFER_CHAR;
yy_current_buffer->yy_ch_buf[yy_n_chars + 1] = YY_END_OF_BUFFER_CHAR;
yytext = &yy_current_buffer->yy_ch_buf[0];
return ret_val;
}
//用文件input_file重新启动当前缓冲区
void yyrestart( FILE *input_file ){
if ( ! yy_current_buffer )
yy_current_buffer = yy_create_buffer( yyin, YY_BUF_SIZE );
yy_init_buffer( yy_current_buffer, input_file );
yy_load_buffer_state();
}
/* 如果在外部定义了YY_STRING表示数据源为字符串
* 字符串parseString由外部初始化,以作为数据源
* parseString,parseCh用来从字符串中读入原始数据*/
#ifdef YY_STRING
char *parseString=0;
static char *parseCh;
static int myinput(char* buf, int max){
int len;
if (parseCh == NULL)
parseCh = parseString;
len = strlen(parseCh);
if (len > max)
len = max;
if (len > 0)
memcpy(buf, parseCh, len);
parseCh += len;
return len;
}
#endif
/////////////////////////////////////////////
int lex(){
//yy_init是一个静态变量初始值为1,表示要初始化
if ( yy_init ){
yy_init = 0;//表示已经执行初始化
//如果用户有自己的初始化函数,则调用它
#ifdef YY_USER_INIT
YY_USER_INIT;
#endif
if ( ! yyin )//如果输入文件为NULL,则使用标准输入
yyin = stdin;
if ( ! yyout )//如果输出文件为NULL,则使用标准输出
yyout = stdout;
if ( ! yy_current_buffer )/*如果当前缓冲区为NULL,则创建*/
yy_current_buffer = yy_create_buffer( yyin, YY_BUF_SIZE );
yy_load_buffer_state();/*使当前缓冲区状态与窗口参数一至*/
}
int rc=LEX_NOTUPLE;
register char c;
while(rc==LEX_NOTUPLE){
c=yyinput();
if(c==EOF){
#ifdef YY_USER_END
YY_USER_END;
#endif
return LEX_END;
}
yytext=yy_c_buf_p-1;
if(c<0)rc=act_chinese(c);//中文
else if(isalpha(c)||(c=='_'))rc=act_identity(c);//标志符
else if(isdigit(c))rc=act_number(c,1);//实数
else switch(c){
case '{':rc=act_comment2(c);break;//注释2
case '\'':rc=act_string(c);break;//字符串或字符
case '(':
c=yyinput();
if(c=='*')rc=act_comment1(c);
else{
rc=LEX_SUCCESS;
result_tuple.flag=o_lbracket;
yyunput(c,yytext);
}
break;
case '=':
rc=LEX_SUCCESS;
result_tuple.flag=o_eq;
break;
case ',':
rc=LEX_SUCCESS;⌨️ 快捷键说明
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