cpp1.cpp

编译原理课程设计

#include <stdio.h>
#include<string.h>
#include<ctype.h>
#include<stdlib.h> 
#include <iostream.h> 
#include <fstream.h>
#define BUFFMAXLEN 100
FILE *out;
char token[20],s[20],filename[25],outfile[25],ch;
char blank[34][10]={"auto","break","case","char","const","continue","default",
   "do","double","else","enum","extern","float","for","goto",
   "if","int","long","register","return","short","signed","sizeof",
   "static","struct","switch","typedef","union","unsigned",
   "void","volatile","while","main"};
int flag=1;

 
void getbe()
    {int readchar(char *ch);
      while(isspace(ch))
 ch=readchar(filename);

    }
void concatenation(char ch)
    {
strcat(token,&ch);
    }
void error()
     {
      if(ch!=-1)
 fputs("\nyour input a data ERROR!",out);
     }
int reserve()
   {int i,m=0;
    for(i=0;i<=34;i++)
{ if(strcmp(token,blank[i])==0)m=1;
}return(m);

   }
int readchar(char * filename)
{
      static FILE *fp = NULL;
      static char buff[BUFFMAXLEN];
      static int bufflen = 0;
      static int buffpos = -1;
      if (fp == NULL)
      {
              if ((fp = fopen(filename,"r")) == NULL)
              {
                      printf("File open error!\n");
                      return 0;
              }
      }
      if (buffpos == -1)
      {
              if (feof(fp))
              {
                      fclose(fp);
                      return -1;
              }
              bufflen = fread(buff,sizeof(char),BUFFMAXLEN,fp);
              buffpos = 0;
      }
      if (buffpos < bufflen)
              ch =  buff[buffpos++];
      if (buffpos >= bufflen)
              buffpos = -1;
	  	  if(ch=='\n') 
flag++;

      return ch;
}

void main()
{
int c,k=0;
char b=' ';
printf("\nPlease input filename:");
      scanf("%s",filename);
printf("\nPlease input outfile name:");
      scanf("%s",outfile);
if((out=fopen(outfile,"w"))==NULL)
    {printf("\ncannot open outfile file!");
      
    }
      ch = b;
while(ch != -1 && ch != 0)
     { strcpy(token,s);
if(k==0)ch=readchar(filename);
   else {ch=b;k=0;}

getbe();
 
if(isalpha(ch))
 {while(isalnum(ch)||ch=='.')
{
  concatenation(ch);
  b=ch=readchar(filename);k=1;
}
   c=reserve();
   if(c==1)fprintf(out,"\n %d: reserved word:%s ",flag, token);
    else 

fprintf(out,"\n %d:ID, name= %s",flag,token);
 }                          
 else
    {if(isdigit(ch))
{while(isdigit(ch)) 
{
concatenation(ch);
b=ch=readchar(filename);k=1;
     }
fprintf(out,"\n %d:INT,val=%s",flag,token); }
     else
 switch(ch)
 { case '+': b=ch=readchar(filename);
     if(ch=='+')fprintf(out,"\n %d: ++",flag,token);
     else {fprintf(out,"\n %d: +",flag,token);k=1;}
     break;
   case '-': b=ch=readchar(filename);
     if(ch=='-')fprintf(out,"\n %d: --",flag,token);
     else {fprintf(out,"\n %d: -",flag,token);k=1;}
     break;
   case '*':fprintf(out,"\n %d: *",flag,token);break;
   case '<': b=ch=readchar(filename);
     if(ch=='=')fprintf(out,"\n %d: <=",flag,token);
     else {fprintf(out,"\n %d: <",flag,token);k=1;}
      break;
   case '=': b=ch=readchar(filename);
     if(ch=='=')fprintf(out,"\n %d: ==",flag,token);
     else {fprintf(out,"\n %d: =",flag,token);k=1;}
     break;
   case '>': b=ch=readchar(filename);
     if(ch=='=')fprintf(out,"\n %d: >=",flag,token);
      else {fprintf(out,"\n %d: >",flag,token);k=1;}
                    case '&': b=ch=readchar(filename);
     if(ch=='&')fprintf(out,"\n %d: &&",flag,token);
     else {fprintf(out,"\n %d: &",flag,token);k=1;}
     break;
   //case '|': b=ch=readchar(filename);
    // if(ch=='|')fprintf(out,"\n %d: ||",flag,token);
    // else { fprintf(out,"\n %d: |",flag,token);break;k=1;}
    // break;
                   case '!': b=ch=readchar(filename);
     if(ch=='=')fprintf(out,"\n %d: !=",flag,token);
     else { fprintf(out,"\n %d: !",flag,token);break;k=1;}
     break;
   case ':': fprintf(out,"\n %d: :",flag,token);break;
   case ',': fprintf(out,"\n %d: ,",flag,token);break;
   case ';': fprintf(out,"\n %d: ;",flag,token);break;
   case '(': fprintf(out,"\n %d: (",flag,token);break;
   case ')': fprintf(out,"\n %d: )",flag,token);break;
   case '{': fprintf(out,"\n %d: {",flag,token);break;
   case '}': fprintf(out,"\n %d: }",flag,token);break;
   case '[': fprintf(out,"\n %d: [",flag,token);break;
   case ']': fprintf(out,"\n %d: ]",flag,token);break;
   case '"': fprintf(out,"\n %d: \"",flag,token);break;
   case '\\': fprintf(out,"\n %d: \\",flag,token);break;
   case '.': fprintf(out,"\n %d: .",flag,token);break;
   case '\'': fprintf(out,"\n %d: \'",flag,token);break;
	   case EOF: fprintf(out,"\n %d: EOF",flag);break;
    default:
 error();
   }

}
     }
  fclose(out);
}