Question

这是我的C扫描仪的一部分，它基于Lex n Yacc，我使用flex，bison和gcc编译器。这是我的yacc文件的一部分。所以我试图将扫描时间缩短到几秒钟，例如扫描仪将在命令行的最后一刻打印扫描时间，因为扫描仪是基于cmd的扫描仪。我已经添加了时间函数（位于此处的最后一个）文件）但作为输出我得到0.00秒。所以我不知道我在哪里犯错误。如果有人对此有任何想法。

%{
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<time.h>

FILE *outFile_p;
FILE *outFile_p1;

extern FILE *yyin;
int counter=0;
int pointer[500];
int pointer2;
char *temp[500];
char *temp2;
int i=0;

int yylex(void);
int yyparse(void);
void yyerror(const char* str)
{
    fprintf(stderr,"error: %s in line: %d please check your function arguments!\n*** NOW:     
    if you are sure your code is correct, \n please insert// before your function call\nin orderto ignore this syntax error\n",str,counter+1); 
}

int yywrap()
{
   return 1;
}

%}

%token STRCPY
%token STRCAT
%token GETS

%left NUMBER

%%

commands:
        {
            fprintf(outFile_p,"%s","#include \"SafeLib.h\"\n");
        } /*empty*/
        | commands command
        ;

command:search1
       |
       search2
       |
       search3
       |
       search4
       ;

       search3:CHAR WORD
       {
           fprintf(outFile_p,"%s%s","char",$2);
       }
       |
       CHAR WORD LB WORD
       {
           printf("pointer_before=%d",pointer);
           temp[i]=$2;
           printf("\ni=%d\n",i);
           if(!strcmp($4,"4"))
           {
               pointer[i]=1;
               printf("pointer=%d",pointer[i]);
           }
           else
           {
               pointer[i]=0;printf("pointer=%d",pointer[i]);
           }
           i++;
           fprintf(outFile_p,"%s%s%s%s","char",$2,$3,$4);
           printf("\ntemp=%s\n",temp[i-1]);
       }
       |
       CHAR WORD LB WORD SIMICOL search4
       {
           printf("pointer_before=%d",pointer);
           temp[i]=$2;
           printf("\ni=%d\n",i);
           if (!strcmp($4,"4"))
           {
               pointer[i]=1;printf("pointer=%d",pointer[i]);
           }
           else
           {
               pointer[i]=0;printf("pointer=%d",pointer[i]);
           }
           i++;
           fprintf(outFile_p,"%s%s%s%s","char",$2,$3,$4);
           printf("\ntemp=%s\n",temp[i-1]);
       }
       |
       NEW WORD
       {
           fprintf(outFile_p,"%s%s","new ",$2);
       }
       |
       NEW CHAR
       {fprintf(outFile_p,"%s%s","new ","char");}
       |
       NEW
       {fprintf(outFile_p,"new");}
       |
       CHAR
       {fprintf(outFile_p,"char");}
       |
       CHAR WORD LB RB
       {fprintf(outFile_p,"%s%s%s%s","char ",$2,$3,$4);}
       |
       WORD LB RB
       {fprintf(outFile_p,"%s%s%s",$1,$2,$3);}
       |
       WORD LB PLUS
       {fprintf(outFile_p,"%s%s%s",$1,$2,$3);}
        |
        GETS LBRAK WORD RBRAK
        {int flipper1=0;int fals=0;temp2=$3;printf("\ntemp2=%s\n",temp2);int j=0;int k=0;
        for (j=0;j<i;j++)
        {if(!strcmp(temp[k],temp2) && pointer[k]==1)
        {fprintf(outFile_p,"%s%s%s%s","/*warning: This function gets() has a buffer overflow security problem*/","gets(",$3,")");
        fprintf(outFile_p1,"\n Very High-Risk Warning::There is a gets() buffer overflow security problem in line %d::It is recommended to use fgets() instead....\n",counter+1);flipper1=1;fals=1;break;}
        if(!strcmp(temp[k],temp2))
        {fprintf(outFile_p,"%s%s%s%s","/*warning: This function gets() has a buffer overflow security problem*/","gets(",$3,")");fprintf(outFile_p1,"\n Very High-Risk Warning::There is a gets() buffer overflow security problem in line %d::It is recommended to use fgets() instead....\n",counter+1);flipper1=1;break;}k++;}if(flipper1==0)
        fprintf(outFile_p,"%s%s%s","gets(",$3,")");}
        |
       ........................................
       .........................................
       .........................................
       |COM {fprintf(outFile_p,";");}
       |LB {fprintf(outFile_p,"[");}
       |RB {fprintf(outFile_p,"]");}

%%

int main(int argc,char*argv[])
{
    FILE *fp;
    if(argc<3)
    {
        printf("please specify the input and out file \n");
        exit(0);
    }
    fp=fopen(argv[1],"r");
    if(!fp)
    {
        printf("couldn't open file for reading \n");
        exit(0);
    }
    outFile_p=fopen(argv[2],"w");
    outFile_p1=fopen(argv[3],"w");
    if(!outFile_p)
    {
        printf("couldn't open temp for writing outfile_p \n");
        exit(0);
    }
    if(!outFile_p1)
    {
        printf("couldn't open temp for writing outfile_p1 \n");
        exit(0);
    }
    clock_t begin, end;
    double time_spent;
    begin = clock();                 
    yyin=fp;
    yyparse();
    fclose(fp);
    fclose(outFile_p);
    end = clock();
    time_spent = (double)(end - begin) / CLOCKS_PER_SEC;
    printf("\nTotal Time for Scanning %f", time_spent);
    }

Answer 1

（Answered in the comments）

@zwol写道：

这是显而易见的，我必须遗漏一些内容，但是：clock的第一次通话应该在致电yyparse之前。

OP写道：

根据@Zack和@ user3121023的建议，我做了一些更改，yacc用于更大的输入文件扫描器显示时间，但对于较小的输入显示0.00秒，是否有任何解决方法... ..

我已经使用gettimeofday函数修复了问题。现在扫描仪显示时间，但我不确定准确度是多少。

扫描时间无法正常显示

1 个答案: