编译原理 语法分析实验

编译原理程序设计实验报告——表达式语法分析器的设计实现班级：计算机1306班姓名：李佳泽学号：20133951实验目标：实现表达式语法分析器的设计实现，使用递归下降子程序、LL1分析法、LR分析法，判断一个表达式是否符合某个语法。

实验内容：流程图：数据结构：struct Node{char content[30]; int type;Node * next;};建立链表用于标识符IT ，常数Ct ，字符存ct ，字符串st ，TOKEN 源程序代码：1.递归调用子程序#include<iostream>#include<string.h>#include<fstream>#include<stdlib.h>#include <stack>using namespace std;#define NOTKEY 50#define iT 00#define cT 01#define sT 02#define CT 03char * kt[5]={"int","main","void","if","char"};char * pt[18]={">=" , "<=" ,"==","=",">","<","+","-","*","/","{","}",",",";","(",")","[","]" };int Ty =3;int dd=0;char vn[]={'E','e','T','t','F'};char vt[]={'i','W','w','(',')','#'};char * right[]={"Te","WTe","","Ft","wFt","","i","(E)"};int seekkt(char * TOKEN){for(int i=0; i<5; i++){if(strcmp(TOKEN,kt[i]) == 0){return i+4;}}return NOTKEY;}int seekpt(char * TOKEN){for(int i=0; i<18; i++){if(strcmp(TOKEN,pt[i]) == 0){return i+10;}}return -1;}int main(){int TOHN();int intN ();int scan();int Right();int print();TOHN();intN ();scan();if(dd==0){cout<<endl;cout<<"分析结果："<<endl;cout<<endl;Right();}print();return 0;}stack <char> s;struct Node{char content[30];int type;Node * next;};Node * itHead;Node * CtHead;Node * ctHead;Node * stHead;Node * TOHead;Node * pp;void E();void T();void F();void TOHN(){TOHead = new Node();strcpy(TOHead->content,"");TOHead->type = 0;TOHead->next = NULL;}void setTON(char * content,int type){Node * p = TOHead ;Node * temp = new Node();while(p->next!=NULL) {p = p->next;}strcpy(temp->content,content);temp->type = type;temp->next = NULL;p->next = temp;}//初始化所有表头结点void intN(){itHead = new Node();strcpy(itHead->content,"");itHead->type = iT;itHead->next = NULL;stHead = new Node();strcpy(stHead->content,"");stHead->type = sT;stHead->next = NULL;CtHead = new Node();strcpy(CtHead->content,"");CtHead->type = CT;CtHead->next = NULL;ctHead = new Node();strcpy(ctHead->content,"");ctHead->type = cT;ctHead->next = NULL;}//创建新节点void setN(char * content,int type,Node * head){Node * p = head ;Node * temp = new Node();int flag = 0;while(p->next!=NULL){if(strcmp(content,p->next->content) == 0){flag = 1;}p = p->next;}if(flag == 0){strcpy(temp->content,content);temp->type = type;temp->next = NULL;p->next = temp;}}void print(){Node * p = TOHead;p = p->next;while(p!=NULL){p = p->next;}}void scan(){//char filename[50];char ch;char a[30];char * TOKEN;int i;FILE * fp;/*printf("输入语法分析的C语言程序（形如D:\\\\test.txt)：\n");scanf("%s",filename);fp = fopen(filename,"r");*/fp=fopen("test.txt","r");ch = fgetc(fp);while(ch!='#'){i = 0;//以字母或者下划线开头,处理关键字或者标识符if((ch>='A' && ch<='Z') || (ch>='a' && ch<='z') || ch == '_'){while((ch>='A' && ch<='Z')||(ch>='a' && ch<='z')||(ch>='0' && ch<='9') || ch == '_'){a[i++] = ch;ch = fgetc(fp);}TOKEN = new char[i+1];memcpy(TOKEN,a,i);TOKEN[i] = '\0';int seekTemp = seekkt(TOKEN);if(seekTemp!=NOTKEY){setTON(TOKEN,seekTemp);}else{setN(TOKEN,iT,itHead);setTON(TOKEN,iT);}fseek(fp,-1L,SEEK_CUR);}//以数字开头，处理数字else if(ch >='0' && ch<='9'){int flag = 0;int flag2 = 0;while(ch >='0' && ch<='9'){a[i++] = ch;ch =fgetc(fp);}//处理floatif(ch == '.'){flag = 1;a[i++] = ch;ch = fgetc(fp);if(ch>='0' && ch<='9'){while(ch>='0' && ch<='9'){a[i++] = ch;ch = fgetc(fp);}}//处理Doubleif(ch == 'E' || ch == 'e'){a[i++] = ch;ch = fgetc(fp);if(ch == '+' || ch == '-'){a[i++] = ch;ch = fgetc(fp);}if(ch >='0' && ch<='9'){a[i++] = ch;ch = fgetc(fp);}}}TOKEN= new char[i+1];memcpy(TOKEN,a,i);TOKEN[i] = '\0';if(flag == 0){setN(TOKEN,CT,CtHead);setTON(TOKEN,CT);}else{setN(TOKEN,CT,CtHead);setTON(TOKEN,CT);}fseek(fp,-1L,SEEK_CUR);}//处理常量字符串else if(ch == '"'){a[i++] = ch;ch = fgetc(fp);while(ch!='"'){a[i++] = ch;ch = fgetc(fp);}a[i++] = ch;ch = fgetc(fp);TOKEN = new char[i+1];memcpy(TOKEN,a,i);TOKEN[i] = '\0';setN(TOKEN,sT,stHead);setTON(TOKEN,sT);fseek(fp,-1L,SEEK_CUR);}//处理常量字符else if(ch == '\''){a[i++] = ch;ch = fgetc(fp);while(ch!='\''){a[i++] = ch;ch = fgetc(fp);}a[i++] = ch;ch = fgetc(fp);TOKEN = new char[i+1];memcpy(TOKEN,a,i);TOKEN[i] = '\0';setN(TOKEN,cT,ctHead);setTON(TOKEN,cT);fseek(fp,-1L,SEEK_CUR);}//结束符else if((ch>='!'&&ch<='/')||(ch>=':'&&ch<='@')||(ch>='['&&ch<='`')||(ch>='('&&ch<='~')){int seektemp;if(ch=='<'||ch=='>'||ch=='='){a[i++] = ch;ch = fgetc(fp);}else {a[i++] = ch;ch = fgetc(fp);}TOKEN = new char[i+1];memcpy(TOKEN,a,i);TOKEN[i] = '\0';seektemp=seekpt(TOKEN);if(seektemp==-1)//结束符不存在{cout<<"结束符错误请检查"<<endl;dd=1;}else{setTON(TOKEN,seektemp);}fseek(fp,-1L,SEEK_CUR);}ch = fgetc(fp);}setTON("#",333);fclose(fp);}void Right(){pp=TOHead;pp=pp->next;E();if(strcmp(pp->content,"#") == 0&&Ty==3){cout<<"RIGHT"<<endl;}else{if(strcmp(pp->content,"#") != 0 &&Ty==3){cout<<"WRONG"<<endl<<endl;cout<<"理由：括号不匹配"<<endl;cout<<endl;}else if (Ty==1){cout<<"WRONG"<<endl<<endl;cout<<"理由：非法字符"<<endl;cout<<endl;}else if(Ty ==2){cout<<"WRONG"<<endl<<endl;cout<<"理由：缺少“）”"<<endl;cout<<endl;}}}void E(){if (Ty != 3) return;T();while (strcmp(pp->content,"+") == 0||strcmp(pp->content,"-") == 0){pp=pp->next;T();}return ;}void T(){if (Ty != 3) return;F();while (strcmp(pp->content,"*") == 0||strcmp(pp->content,"/") == 0){pp=pp->next;F();}return ;}void F(){if (Ty != 3) return;if (pp->type == CT||pp->type == iT){pp=pp->next;return;}elseif(strcmp(pp->content,"(") == 0){pp=pp->next;E();if (strcmp(pp->content,")") == 0){pp=pp->next;return;}else{Ty = 2;return;}}else{Ty = 1;return;}}2.LL1分析法#include<iostream>#include<string.h>#include<fstream>#include<stdlib.h>#include <stack>using namespace std;#define NOTKEY 50#define iT 00#define cT 01#define sT 02#define CT 03char * kt[5]={"int","main","void","if","char"};char * pt[18]={">=" , "<=" ,"==","=",">","<","+","-","*","/","{","}",",",";","(",")","[","]" }; int dd=0;int sss=0;int seekkt(char * TOKEN){for(int i=0; i<5; i++){if(strcmp(TOKEN,kt[i]) == 0){return i+4;}}return NOTKEY;}int seekpt(char * TOKEN){for(int i=0; i<18; i++){if(strcmp(TOKEN,pt[i]) == 0){return i+10;}}return -1;}int main(){int TOHN();int intN ();int scan();int print();int wrong();TOHN();intN ();scan();print();if(dd==0){cout<<"分析结果："<<endl<<endl; wrong();cout<<endl;}return 0;}stack <char*> s;struct Node{char content[30];int type;Node * next;};Node * itHead;Node * CtHead;Node * ctHead;Node * stHead;Node * TOHead;Node * pp;void TOHN(){TOHead = new Node();strcpy(TOHead->content,"");TOHead->type = 0;TOHead->next = NULL;}void setTON(char * content,int type){Node * p = TOHead ;Node * temp = new Node();while(p->next!=NULL) {p = p->next;}strcpy(temp->content,content);temp->type = type;temp->next = NULL;p->next = temp;}//初始化所有表头结点void intN(){itHead = new Node();strcpy(itHead->content,"");itHead->type = iT;itHead->next = NULL;stHead = new Node();strcpy(stHead->content,"");stHead->type = sT;stHead->next = NULL;CtHead = new Node();strcpy(CtHead->content,"");CtHead->type = CT;CtHead->next = NULL;ctHead = new Node();strcpy(ctHead->content,"");ctHead->type = cT;ctHead->next = NULL;}//创建新节点void setN(char * content,int type,Node * head){Node * p = head ;Node * temp = new Node();int flag = 0;while(p->next!=NULL){if(strcmp(content,p->next->content) == 0){flag = 1;}p = p->next;}if(flag == 0){strcpy(temp->content,content);temp->type = type;temp->next = NULL;p->next = temp;}}//打印链表void print(){Node * p = TOHead;p = p->next;while(p!=NULL){p = p->next;}}//扫描程序void scan(){//char filename[50];char ch;char array[30];char * TOKEN;int i;FILE * fp;/*printf("输入语法分析的C语言程序（形如test.txt)：\n");scanf("%s",filename);fp = fopen(filename,"r");*/fp=fopen("test.txt","r");ch = fgetc(fp);while(ch!='#'){i = 0;if((ch>='A' && ch<='Z') || (ch>='a' && ch<='z') || ch == '_'){while((ch>='A' && ch<='Z')||(ch>='a' && ch<='z')||(ch>='0' && ch<='9') || ch == '_'){array[i++] = ch;ch = fgetc(fp);}TOKEN = new char[i+1];memcpy(TOKEN,array,i);TOKEN[i] = '\0';int seekTemp = seekkt(TOKEN);if(seekTemp!=NOTKEY){setTON(TOKEN,seekTemp);}else{setN(TOKEN,iT,itHead);setTON(TOKEN,iT);}fseek(fp,-1L,SEEK_CUR);}//以数字开头，处理数字else if(ch >='0' && ch<='9'){int flag = 0;int flag1 = 0;while(ch >='0' && ch<='9'){array[i++] = ch;ch =fgetc(fp);}//处理floatif(ch == '.'){flag1 = 1;array[i++] = ch;ch = fgetc(fp);if(ch>='0' && ch<='9'){while(ch>='0' && ch<='9'){array[i++] = ch;ch = fgetc(fp);}}//处理Doubleif(ch == 'E' || ch == 'e'){array[i++] = ch;ch = fgetc(fp);if(ch == '+' || ch == '-'){array[i++] = ch;ch = fgetc(fp);}if(ch >='0' && ch<='9'){array[i++] = ch;ch = fgetc(fp);}}}TOKEN= new char[i+1];memcpy(TOKEN,array,i);TOKEN[i] = '\0';if(flag == 0){setN(TOKEN,CT,CtHead);setTON(TOKEN,CT);}else{setN(TOKEN,CT,CtHead);setTON(TOKEN,CT);}fseek(fp,-1L,SEEK_CUR);}//处理常量字符串else if(ch == '"'){array[i++] = ch;ch = fgetc(fp);while(ch!='"'){array[i++] = ch;ch = fgetc(fp);}array[i++] = ch;ch = fgetc(fp);TOKEN = new char[i+1];memcpy(TOKEN,array,i);TOKEN[i] = '\0';setN(TOKEN,sT,stHead);setTON(TOKEN,sT);fseek(fp,-1L,SEEK_CUR); }//处理常量字符else if(ch == '\''){array[i++] = ch;ch = fgetc(fp);while(ch!='\''){array[i++] = ch;ch = fgetc(fp);}array[i++] = ch;ch = fgetc(fp);TOKEN = new char[i+1];memcpy(TOKEN,array,i);TOKEN[i] = '\0';setN(TOKEN,cT,ctHead);setTON(TOKEN,cT);fseek(fp,-1L,SEEK_CUR);}//结束符else if((ch>='!'&&ch<='/')||(ch>=':'&&ch<='@')||(ch>='['&&ch<='`')||(ch>='('&&ch<='~')){int seektemp;if(ch=='<'||ch=='>'||ch=='='){array[i++] = ch;ch = fgetc(fp);}else {array[i++] = ch;ch = fgetc(fp);}TOKEN = new char[i+1];memcpy(TOKEN,array,i);TOKEN[i] = '\0';seektemp=seekpt(TOKEN);if(seektemp==-1)//结束符不存在{cout<<"结束符错误请检查"<<endl;dd=1;}else{setTON(TOKEN,seektemp);}fseek(fp,-1L,SEEK_CUR);}ch = fgetc(fp);}setTON("#",333);fclose(fp);}/*内容类码( 24Aa 0+ 16) 25* 1888.2 3/ 19- 17# 123*/void ssss(){if(s.top()=="E"){if((pp->type==iT)||(pp->type==CT)){s.pop();s.push("E1");s.push("T");sss=1;return;}if(pp->type==24){s.pop();s.push("E1");s.push("T");sss=1;return;}if(s.top()=="E1"){if((pp->type==16)||(pp->type==17)){s.pop();s.push("E1");s.push("T");s.push("w0");sss=1;return;}if(pp->type==25){s.pop();sss=1;return;}if(pp->type==333){s.pop();sss=1;return;}}if(s.top()=="T"){if((pp->type==iT)||(pp->type==CT)){s.pop();s.push("T1");s.push("F");sss=1;return;if(pp->type==24){s.pop();s.push("T1");s.push("F");sss=1;return;}//处理float}if(s.top()=="T1"){if((pp->type==16)||(pp->type==17)){s.pop();;sss=1;return;}if((pp->type==18)||(pp->type==19)){s.pop();s.push("T1");s.push("F");s.push("w1");sss=1;return;}if(pp->type==25){s.pop();//处理floatsss=1;return;}if(pp->type==333){s.pop();sss=1;return;}}if(s.top()=="F"){if((pp->type==iT)||(pp->type==CT)){s.pop();s.push("I");sss=1;return;}if(pp->type==24){s.pop();s.push(")");s.push("E");s.push("(");sss=1;return;}}}void two(){string content(&pp->content[0],&pp->content[strlen(pp->content)]);if(pp->type==16||pp->type==17)content="w0";if(pp->type==18||pp->type==19)content="w1";if(pp->type==iT||pp->type==CT)content="I";if(strcmp(s.top(),content.c_str())==0){s.pop();pp=pp->next;sss=1;return;}}void wrong(){s.push("#");s.push("E");pp=TOHead;pp=pp->next;while(!s.empty()){sss=0;ssss();two();if (sss==0){cout<<"WRONG";break;}}if (sss!=0){cout<<"RIGHT";}}程序运行结果：（截屏）递归调用子程序输入：Aa+Bb)*(88.2/3)#输出：输入：(Aa+Bb)*(88.2/3)#输出：LL1分析法输入：Aa+Bb)*(88.2/3)#输出：输入：(Aa+Bb)*(88.2/3)#输出：。