my.cpp

很经典的一个词法分析程序。。希望大家能够支持

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define LENGTH 61
#define N 100

void Scanner();
void ScannerInit();
void IsAlpha();
void IsNumber();
void IsAnotation();
void IsChar();
void IsOther();
void OutPut();
void Error(int a);
int WordHave();
typedef struct token
{int label;
char name[30];
int code;
int addr;
}token;
typedef struct KeyWord
{char name[30];
int code;
}KeyWord;
typedef struct symble
{int number;
int type;
char name[30];
}symble;

char ch;
int var_count;
int error_count;
int label_count;
int code_count;
int addr_count;
int LineOfPro;
char filename[30];
FILE *KeyFin;
FILE *SourceFin;
FILE *TokenFout;
FILE *SymbleFout;
KeyWord key[LENGTH];
token CurrentToken;
symble CurrentSimble;
symble SymbleList[N];

int strcmp(char *s,char *t)
    {for(;*s==*t;s++,t++)
         if(*s==0)
         return 0;
     return 1;
    }

int main()
{
int i=0,j=0;
code_count=0;
LineOfPro=0;
var_count=0;
addr_count=1;
label_count=1;
for(i=0;i<N;i++){SymbleList[i].number=0;
                 SymbleList[i].type=0;
                 for(j=0;j<30;j++)SymbleList[i].name[j]='\0';
                }
Scanner();
return 0;
}

void Scanner()
{
int i=0;
error_count=0;
ScannerInit();
printf("  -----------------------------------\n");
printf("  |            词法分析器          |\n");
printf("  -----------------------------------\n");
printf("输入源文件名：\n");
for(;;){scanf("%c",&filename[i]);
        if(filename[i]==10)
        break;
        i++;
        }
filename[i]='\0';
if((SourceFin=fopen(filename,"r"))==NULL)
   {printf("the source can not open!%s.\n",filename);
   exit(1);
   }
if((TokenFout=fopen("token.txt","w+"))==NULL)
   {printf("token.txt can not open!");
   exit(1);
   }
if((SymbleFout=fopen("symble.txt","w+"))==NULL)
   {printf("symble.txt can not open!");
   exit(1);
   }
ch=fgetc(SourceFin);
while(ch!=EOF)
{   for(i=0;i<30;i++)CurrentToken.name[i]='\0';
    if((ch>47)&&(ch<58))IsNumber();
    else{
           if(((ch>64)&&(ch<90))||((ch>96)&&(ch<123))||ch=='_')IsAlpha();
           else {if(ch=='/')IsAnotation();
                 else if(ch=='\'')IsChar();
                         else IsOther();
                 }
          }
}
fclose(SourceFin);
fclose(TokenFout);
fclose(SymbleFout);
printf("分析完毕。\n");
}

void ScannerInit()
{
int i=1;
int k=0;
if((KeyFin=fopen("source.txt","r"))==NULL)
    {printf("ni.txt cannot open.\n");
    exit(1);
    }
for(i=0;i<60;i++)for(k=0;k<30;k++)key[i].name[k]='\0';
for(i=1;i<60;i++){fscanf(KeyFin,"%s%d",key[i].name,&key[i].code);
fclose(KeyFin);
  }
}
void IsNumber()
{ int k=0;
  int flag=0;
  char ch1;
  while((ch>47)&&(ch<58))
     {  CurrentToken.name[k++]=ch;
        ch=fgetc(SourceFin);
        if(ch=='.'){flag=1;break;}
     }
CurrentToken.code=28;
CurrentToken.addr=addr_count++;
CurrentToken.label=label_count++;
if(flag)
   {   ch1=fgetc(SourceFin);
       if((ch1>47)&&(ch<58)) CurrentToken.name[k++]=ch;
       else Error(2);
       ch=ch1;
       while((ch>47)&&(ch<58))
             {   CurrentToken.name[k++]=ch;
                 ch=fgetc(SourceFin);
             }
        CurrentToken.code=29;
        if(ch=='.')
           {Error(2);
            while((ch>47)&&(ch<58))ch=fgetc(SourceFin);
           }
   }
  if(((ch>64)&&(ch<90))||((ch>96)&&(ch<123)))
    {Error(2);
     while(((ch>64)&&(ch<90))||((ch>96)&&(ch<123)))
          { ch=fgetc(SourceFin);
            while((ch>47)&&(ch<58))
            ch=fgetc(SourceFin);
          }
     }
     OutPut();
}

void IsAlpha()
{  int i=0,h=0;
   while(((ch>64)&&(ch<90))||((ch>96)&&(ch<123))||ch=='_')
        {  CurrentToken.name[i++]=ch;
           ch=fgetc(SourceFin);
        }
   for(i=1;i<LENGTH;i++)
      { h=strcmp(CurrentToken.name,key[i].name);
      if(!h)break;
      }
    if(!h){ CurrentToken.code=key[i].code;
            CurrentToken.addr=-1;
          }
    else{ CurrentToken.code=27;
          CurrentToken.addr=addr_count++;
        }
    CurrentToken.label=label_count++;
    OutPut();
}

void IsAnotation()
{char ch1;
ch1=ch;
ch=fgetc(SourceFin);
if(ch=='*')for(;;){   ch=fgetc(SourceFin);
                      if(ch==EOF){Error(3);break;}
                      if(ch=='*')
                         {  ch1=ch;ch=fgetc(SourceFin);
                         if(ch=='/'){  ch=fgetc(SourceFin);break;}
                         }
                   }
                   else{   CurrentToken.name[0]='/';
                           CurrentToken.code=39;
                           CurrentToken.addr=-1;
                           CurrentToken.label=label_count++;
                           OutPut();
                       }
}

void IsChar()
{ int i=0;
  for(;;){ ch=fgetc(SourceFin);
           CurrentToken.code=30;
           if(ch!='\'')CurrentToken.name[i++]=ch;
           else break;
          }
  CurrentToken.addr=addr_count++;
  CurrentToken.label=label_count++;
  ch=fgetc(SourceFin);
}

void IsOther()
{  char ch1;
   int i;
   for(i=0;i<30;i++)
   CurrentToken.name[i]='\0';
   switch(ch){  case'(':CurrentToken.name[0]='(';
                CurrentToken.code=32;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case')':CurrentToken.name[0]=')';
                CurrentToken.code=33;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case'*':CurrentToken.name[0]='*';
                CurrentToken.code=34;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case'+':CurrentToken.name[0]='+';
                CurrentToken.code=35;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case',':CurrentToken.name[0]=',';
                CurrentToken.code=37;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case'_':CurrentToken.name[0]='_';
                CurrentToken.code=36;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case'.':CurrentToken.name[0]='.';
                CurrentToken.code=38;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case':':ch1=ch;
                        ch=fgetc(SourceFin);
                        if(ch!='='){ CurrentToken.name[0]=':';
                                     CurrentToken.code=40;
                                     CurrentToken.addr=-1;
                                     CurrentToken.label=label_count++;
                                     OutPut();
                                    }
                        else {CurrentToken.name[0]=':';
                              CurrentToken.name[1]='=';
                              CurrentToken.code=41;
                              CurrentToken.addr=-1;
                              CurrentToken.label=label_count++;
                              OutPut();
                              ch=fgetc(SourceFin);
                              }
                break;
                case';':CurrentToken.name[0]=';';
                CurrentToken.code=42;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case'<':ch1=fgetc(SourceFin);
                        if(ch1=='='){ CurrentToken.name[0]='<';
                                      CurrentToken.name[1]='=';
                                      CurrentToken.code=44;
                                      CurrentToken.addr=-1;
                                      CurrentToken.label=label_count++;
                                      OutPut();
                                      ch1=fgetc(SourceFin);
                                     }
                                     else{ if(ch1=='>')
                                           {  CurrentToken.name[0]='<';
                                              CurrentToken.name[1]='>';
                                              CurrentToken.addr=45;
                                              CurrentToken.label=label_count++;
                                              OutPut();
                                              ch1=fgetc(SourceFin);
                                           }
                                           else{ CurrentToken.name[0]='<';
                                                 CurrentToken.code=43;
                                                 CurrentToken.addr=-1;
                                                 CurrentToken.label=label_count++;
                                                 OutPut();
                                               }
                                           }
                                           ch=ch1;
                break;
                case'=':CurrentToken.name[0]='=';
                CurrentToken.code=46;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
                break;
                case'>':ch1=fgetc(SourceFin);
                        if(ch=='='){ CurrentToken.name[0]='>';
                                     CurrentToken.name[1]='=';
                                     CurrentToken.code=48;
                                     CurrentToken.addr=-1;
                                     CurrentToken.label=label_count++;
                                     OutPut();
                                     ch1=fgetc(SourceFin);
                                   }
                        else{ CurrentToken.name[0]='>';
                              CurrentToken.code=47;
                              CurrentToken.addr=-1;
                              CurrentToken.label=label_count++;
                              OutPut();
                            }
                            ch=ch1;
                break;
                case'!':CurrentToken.name[0]='!';
                CurrentToken.code=49;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
				break;
                case'%':CurrentToken.name[0]='%';
                CurrentToken.code=50;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
				break;
                case'{':CurrentToken.name[0]='{';
                CurrentToken.code=51;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
				break;
                case'}':CurrentToken.name[0]='}';
                CurrentToken.code=52;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
				break;
				case'-':CurrentToken.name[0]='-';
                CurrentToken.code=53;
                CurrentToken.addr=-1;
                CurrentToken.label=label_count++;
                OutPut();
                ch=fgetc(SourceFin);
				break;
                case 10:LineOfPro++;
                        ch=fgetc(SourceFin);
                break;
                case 13:LineOfPro++;
                        ch=fgetc(SourceFin);
                break;
                case' ':ch=fgetc(SourceFin);
                break;
                case EOF:Error(4);
                break;
                default:Error(1);
                       ch=fgetc(SourceFin);
                break;
   }
}

void OutPut()
{ int flag,i=0;
  int k;
  if((CurrentToken.code==27)||(CurrentToken.code==30)||(CurrentToken.code==28)||(CurrentToken.code==29))
    { CurrentSimble.number=CurrentToken.addr;
      CurrentSimble.type=CurrentToken.code;
      strcpy(CurrentSimble.name,CurrentToken.name);
      flag=WordHave();
      if(((CurrentToken.code==27)&&(flag==1))||(CurrentToken.code==30)||(CurrentToken.code==28)||(CurrentToken.code==29))
        fprintf(SymbleFout,"%3d %3d %s\n",CurrentSimble.number,CurrentSimble.type,CurrentSimble.name);
    }
    for(;;)if(CurrentToken.name[i++]=='\0')break;
    fprintf(TokenFout,"%3d %s",CurrentToken.label,CurrentToken.name);
    printf("%3d %s",CurrentToken.label,CurrentToken.name);
    for(k=20-i;k>0;k--) { fprintf(TokenFout,"");
                          printf("");
                        }
    fprintf(TokenFout,"%3d %3d\n",CurrentToken.code,CurrentToken.addr);
    printf("%3d %3d\n",CurrentToken.code,CurrentToken.addr);
}

void Error(int a)
{   error_count++;
    switch(a){  case 1: printf("error  %2d 非法字符在 %3d行.\n",error_count,LineOfPro++);
                break;
                case 2: printf("error  %2d实常数出错在 %3d行.\n",error_count,LineOfPro++);
                break;
                case 3: printf("error  %2d没有匹配的注释符‘*/’.\n",error_count);
                break;
                case 4: printf("error  %2d非正常结束！\n",error_count);
                break;
                default: break;
             }
}

int WordHave()
{int flag,i=0;
 for(i=0;i<var_count;i++)
    { flag=strcmp(CurrentSimble.name,SymbleList[i].name);
      if(flag==0){  CurrentToken.addr=SymbleList[i].number;
                    return 0;
                  }
    }
 SymbleList[var_count].number=CurrentToken.addr;
 SymbleList[var_count].type=CurrentToken.code;
 strcpy(SymbleList[var_count].name,CurrentToken.name);
 var_count++;
 return 1;
}