WHILE循环语句的翻译程序设计（递归下降法、简单优先法、LR方法、LL（1）法、输出四元式、输出三地址表示）

#include <stdio.h> #include <ctype.h> #include <string.h> #include <fstream> #include <iostream> using namespace std; ifstream infile("in.txt",ios::in); ofstream outfc("cifafenxi.txt",ios::out); ofstream outfy("yufafenxi.txt",ios::out); #define STACKSIZE 100 #define BUFFSIZE 100 #define NULL 0 struct structure { int p; char*adr; }Buff[BUFFSIZE], TheStack[STACKSIZE]; int Top; char middle[20]; int n=0; int Tn=1; int t=0; typedef enum youxianguanxi{ ER=0, GT, LT, EQ }; youxianguanxi PreTable[17][17]; void Precedence() {int i,j; for(i=0;i<=16;i++) for(j=0;j<=16;j++) PreTable[i][j]=ER; PreTable[1][0]=LT; for(i=0;i<=8;i++) { PreTable[i][8]=LT; PreTable[i][10]=LT; PreTable[i][11]=LT; PreTable[i][14]=LT; } PreTable[1][8]=ER; PreTable[1][11]=ER; PreTable[1][14]=ER; PreTable[6][14]=PreTable[7][14]=EQ; PreTable[1][12]=PreTable[0][13]=EQ; PreTable[0][15]=LT; PreTable[2][15]=PreTable[3][15]=PreTable[4][15]=PreTable[5][15]=PreTable[8][15]=EQ; for(i=9;i<=11;i++) for(j=1;j<8;j++) PreTable[i][j]=GT; PreTable[9][5]=PreTable[11][5]=ER; PreTable[10][5]=EQ; PreTable[9][9]=PreTable[10][9]=PreTable[11][9]=GT; PreTable[9][16]=PreTable[10][16]=PreTable[11][16]=GT; PreTable[12][16]=GT; PreTable[13][1]=EQ; PreTable[14][1]=PreTable[14][2]=PreTable[14][3]=PreTable[14][4]=GT; PreTable[14][6]=PreTable[14][7]=EQ; PreTable[14][9]=PreTable[14][16]=GT; PreTable[15][1]=PreTable[15][16]=GT; PreTable[15][2]=PreTable[15][3]=PreTable[15][4]=PreTable[15][9]=EQ; PreTable[16][0]=PreTable[16][10]=LT; } void InitStack(); bool Push(int t,char*addr); bool Pop(int c); void InitStack() { Top = 0; Push(16,NULL); } bool Push(int i,char*pt) { if (Top < STACKSIZE) { TheStack[Top].p= i; TheStack[Top++].adr=pt; return true; } else return false; } structure Pop() { structure c; if (Top > 0) { c = TheStack[--Top]; return c; } } structure GetValue() { if (Top > 0) return TheStack[Top-1]; } void PrintStack() { int i; for (i=0; i<Top; i++) switch (TheStack[i].p) {case 0 : printf("while "); outfy<<"while "; break; case 1 : printf("do "); outfy<<"do "; break; case 2 : printf("> "); outfy<<"> "; break; case 3 : printf("< "); outfy<<"> "; break; case 4 : printf("== "); outfy<<"== "; break; case 5 : printf("= "); outfy<<"= "; break; case 7: if(t==1) { printf("/ "); outfy<<"/ "; } else { printf("* "); outfy<<"* "; } break; case 6 : if(t==1) { printf("- "); outfy<<"- "; } else { printf("+ "); outfy<<"+ "; } break; case 10 : printf("i "); outfy<<"i "; break; case 11 : printf("d "); outfy<<"d "; break; case 12 : printf("S "); outfy<<"S "; break; case 13 : printf("C "); outfy<<"C "; break; case 14 : printf("E "); outfy<<"E "; break; case 15 : printf("F "); outfy<<"F "; break; default : printf("# "); outfy<<"# "; } printf("\n"); outfy<<endl; } void print(char*p) {if(p!=NULL) if(*p=='#') { p++; printf("T%c",*p); } else if(isdigit(*p)) { while(isdigit(*p)) printf("%c",*p++); } else { while(isalnum(*p)) printf("%c",*p++); } else printf("?"); } void Print(char*p) {if(p!=NULL) if(*p=='#') { p++; outfc<<*p; } else if(isdigit(*p)) { while(isdigit(*p)) outfc<<*p++; } else { while(isalnum(*p)) outfc<<*p++; } else outfc<<"?"; } youxianguanxi GetPrecedence(const int i, const int j) { if (i!=-1 && j!=-1) return PreTable[i][j]; } void Reduce() { structure outstring[10]; int len; int c; len=1; outstring[len].p=GetValue().p; outstring[len].adr=Pop().adr; c=GetValue().p; while (GetPrecedence(c,outstring[len].p)== EQ) { outstring[++len].p=GetValue().p; outstring[len].adr=Pop().adr; c=GetValue().p; if(len==3&&outstring[1].p==14&&outstring[3].p==14) break; } if(len==1&&(outstring[1].p==10||outstring[1].p==11)) { print(outstring[1].adr); Push(14,outstring[1].adr); } else if (len==1&&outstring[1].p==14) Push(15,outstring[1].adr); else if (len==3&&outstring[1].p==14&&outstring[3].p==14) { middle[n++]='#'; middle[n++]=Tn++; Push(15,&middle[n-2]); } else if (len==3&&outstring[1].p==9) Push(14,outstring[1].adr); else if (len==4&&outstring[1].p==12) Push(12,NULL); else if (len==3&&outstring[1].p==15&&outstring[3].p==10) { Push(12,NULL); } else if (len>=3&&outstring[len].p==15) { middle[n++]='#'; middle[n++]=Tn++; Push(13,&middle[n-2]); } else Push(-1,NULL); } bool Syntax() { int ip = 0; printf("语法分析过程为:\n"); InitStack(); while (true) { if (GetValue().p==12 && Buff[ip].p==16&&Top==2) { printf("语法分析正确结束!\n"); return true; } else if (GetValue().p==-1) { printf("语法错误!\n"); return false; } else { switch (GetPrecedence(GetValue().p, Buff[ip].p)) { case LT: case EQ: Push(Buff[ip].p,Buff[ip].adr); ip++; PrintStack(); break; case GT: Reduce(); PrintStack(); break; default: printf("语法错误!\n"); return false; } } } } void Lexical() {char*pch,str[100],*pstr,*pt; char ch[200]={'\0'}; int length; int i=0,u=-1; while(!infile.eof()) { u++; ch[u]=infile.get(); } pch=ch; length=strlen(ch); pch=ch; printf("\n词法分析结果是:\n"); while(pch<=ch+length) {pstr=str; while(*pch==' '||*pch=='('||*pch==')') pch++; pt=pch; if(isalpha(*pch)) { while(isalnum(*pch)) { *pstr=*pch; pstr++; pch++; } *pstr='\0'; if(strcmp(str,"while")==0) { printf("关键字while "); outfc<<"关键字while "<<endl; Buff[i].p=0; Buff[i++].adr=NULL; } else if(strcmp(str,"do")==0) { printf("关键字do "); outfc<<"关键字do "<<endl; Buff[i].p=1; Buff[i++].adr=NULL; } else { printf("标识符 "); outfc<<"标识符 "; printf(str); outfc<<str<<endl; Buff[i].p=10; Buff[i++].adr=pt; } } else if(isdigit(*pch)) { pt=pch; printf("数字"); outfc<<"数字"; while(isdigit(*pch)) { printf("%c",*pch); outfc<<*pch; pch++; } outfc<<endl; printf(" "); outfc<<" "; Buff[i].p=11; Buff[i++].adr=pt; } if(*pch=='=') { if(*(pch+1)=='=') { printf("等于=="); outfc<<"等于=="<<endl; printf(" "); pch++; pch++; Buff[i].p=4; Buff[i++].adr=NULL; } else {printf("赋值="); outfc<<"赋值="<<endl; printf(" "); pch++; Buff[i].p=5; Buff[i++].adr=NULL; } } else if(*pch=='*') { printf("乘号* "); outfc<<"乘号* "<<endl; pch++; Buff[i].p=7; Buff[i++].adr=NULL; } else if(*pch=='+') { printf("加号+ "); outfc<<"加号+ "<<endl; pch++; Buff[i].p=6; Buff[i++].adr=NULL; } else if(*pch=='-') { t=1; printf("减号- "); outfc<<"减号- "<<endl; pch++; Buff[i].p=6; Buff[i++].adr=NULL; } else if(*pch=='/') { t=1; printf("除号/ "); outfc<<"除号/ "<<endl; pch++; Buff[i].p=7; Buff[i++].adr=NULL; } else if(*pch =='<') { printf("小于号< "); outfc<<"小于号< "<<e