编译原理设计c语言词法解析总结器

编译原理设计c语言词法分析总结器编译原理设计c语言词法分析总结器18/18编译原理设计c语言词法分析总结器编译原理课程设计报告题目：学院：教师：姓名：学号：班级：评分：署名：编译原理课程设计一：设计c语言的词法剖析器一、实验目的认识高级语言单词的分类，认识状态图以及怎样表示并辨别单词规那么，掌握状态图到识别程序的编程，加深对词法原理的理解。二、实验要求认识高级语言单词的分类，认识状态图以及怎样表示并辨别单词规那么，掌握状态图到识别程序的编程。三、实验设计．单词分类及表示语言的子集分类1〕表记符：以字母开头的字母数字串2〕整数或浮点型。3〕保存字：for,while,do,else,if,static,int,sizeof,break,continue4〕运算符：+，-，*，/，%,>,<,=,!=,==,<=,>=,!,&,&&,||;5〕界符："(",")",",",":",";","{","}"单词二元组〔单词分类号、单词自己值〕单词分类号表记符1整数或浮点型2保存字3运算符4界符5词法剖析器的设计算法设计纲要设计从文件中逐一读取字符，只需这五大类的状态序列那么持续读取，否那么回退字符，在对应类型进行查找，输出单元二次组至另一文件夹。开始打开txt文件读取c语言代码扫描Y能否读取到Y相应字符Y常数？表记符保存字运算符界符？记录标号结束状态图设计输入输出设计输入：经过文件指针从文件中一个一个读取字符输出：输出单词二元组至文件。格式为〔种别码，值〕主要函数voidGetchar(FILE*fp)//读入一个字符voidGetBC(FILE*fp)//读入一个非空字符voidcontacat()//连结字符intletter()//判断能否为字母intdigit()//判断能否为字母voidretract(FILE*fp,char*c)//回退intreserve(chark)//办理保存字intsysmbol(identifier*id)//办理表记符，查找符号表并寄存地点假定没有那么增添intconstant(constnumber*con)//存入常数表，并返回它在常数表中的地点voidTofile(intnum,intval,identifier*id,constnumber*con,FILE*fw)//写到文件voidWordAnalyze(chark,char*c,charCODE,identifier*id,constnumber*con,FILE*fp,FILE*fw)//词法剖析函数四、结果测试文件输入intmain(){inta=1,b=3;if(a>1)b=b-2;}输出结果：结论：程序输出结果与希望输出结果符合。四、收获与感想经过我本次课程设计掌握了词法剖析器设计的根本方法与有关知识。词法剖析的重点是明确各种字符的状态变换过程。同时协助表记符、常量构造体与保存字表用于查找返回值。同时我也对剖析问题解决问题有了更深入全面的认识与理解。面对一个大的问题，需要理清解决的步骤再将其分解成小的模块逐一解决最后再串连在一同，问题就会变得更简单，思路也会更为清楚。五、实验代码#include<iostream>usingnamespacestd;#defineLENGTH10charch;char*CODE[]={"identifier","constant","keyword"/*保存字*/,"+","-","*","/","<","<=",">",">=","!=","==","=","(",")",",",":",";","{","}"};char*k[]={"for","while","do","else","if","static","int","sizeof","break","continue"};//保存字chartoken[16];//寄存办理后的字符串表记符构造体typedefstruct{char*I[256];intlen;}identifier;typedefstruct{intcont[300];intlen;}constnumber;读入一个字符voidGetchar(FILE*fp){if((ch=getc(fp))==EOF)exit(1);}读入一个非空字符voidGetBC(FILE*fp){while(ch==''||ch=='\n'||ch==9)Getchar(fp);}连结字符voidcontacat(){char*cht=&(ch);strcat_s(token,cht);}判断能否为字母intletter(){returnisalpha(ch);}intdigit(){returnisdigit(ch);}回退voidretract(FILE*fp,char*c){inta=ftell(fp);fseek(fp,0,SEEK_SET);fprintf_s(fp,"%c",ch);ch='';fseek(fp,a,SEEK_SET);}办理保存字intreserve(chark){inti;for(i=0;i<LENGTH;i++){if(strcmp(token,k[i])==0)return(i+1);}return0;}办理表记符，查找符号表并寄存地点假定没有那么增添intsysmbol(identifier*id){inti;for(i=0;i<id->len;i++)if(strcmp(token,id->I[i])==0)returni+1;if(id->len>256){cout<<"error";}id->I[id->len]=token;id->len++;returnid->len;}数字字符串转变为整数intstr_to_num(){inti=0;intk=token[i]-'0';for(i=1;token[i]!='\0';i++){k=k*10+token[i]-'0';}returnk;}存入常数表，并返回它在常数表中的地点intconstant(constnumber*con){con->cont[con->len]=str_to_num();con->len++;returncon->len;}写到文件voidTofile(intnum,intval,identifier*id,constnumber*con,FILE*fw){intnum_=num;fprintf_s(fw,"(%d,",num);if(num>=4)fprintf_s(fw,"%s",CODE[num-1]);if(num<4){switch(num){case1:fprintf_s(fw,"%s",id->I[val-1]);break;case2:fprintf_s(fw,"%d",con->cont[val-1]);break;case3:fprintf_s(fw,"%s",k[val-1]);break;}}fprintf_s(fw,")\n");}voiderror(FILE*fw){cout<<"(Error,"<<ch<<")"<<endl;fprintf_s(fw,"(Error,%c\n)",ch);}//词法剖析函数voidWordAnalyze(chark,char*c,charCODE,identifier*id,constnumber*con,FILE*fp,FILE*fw){intnum,val;strcpy_s(token,"");//初始化为空字符串Getchar(fp);GetBC(fp);if((ch>='A'&&ch<='Z')||(ch>='a'&&ch<='z'))//剖析表记符和保存字{假定字符为A~Z或0~9，那么持续读取while(letter()||digit()){contacat();Getchar(fp);}retract(fp,c);num=reserve(k);if(num!=0)Tofile(3,num,id,con,fw);else{val=sysmbol(id);Tofile(1,val,id,con,fw);}}elseif(digit())//办理常数{while(digit()){contacat();Getchar(fp);}retract(fp,c);val=constant(con);Tofile(2,val,id,con,fw);}else//剖析符号{switch(ch){case'<':Getchar(fp);if(ch=='=')Tofile(9,0,id,con,fw);else{retract(fp,c);Tofile(8,0,id,con,fw);}break;case'>':Getchar(fp);if(ch=='=')Tofile(11,0,id,con,fw);else{retract(fp,c);Tofile(10,0,id,con,fw);}break;case'=':Getchar(fp);if(ch=='=')Tofile(13,0,id,con,fw);else{retract(fp,c);Tofile(14,0,id,con,fw);}break;case'!':Getchar(fp);if(ch=='=')Tofile(12,0,id,con,fw);elseerror(fw);break;case'+':Tofile(4,0,id,con,fw);break;case'-':Tofile(5,0,id,con,fw);break;case'*':Tofile(6,0,id,con,fw);break;case'/':Tofile(7,0,id,con,fw);break;case'(':Tofile(15,0,id,con,fw);break;case')':Tofile(16,0,id,con,fw);break;case',':Tofile(17,0,id,con,fw);break;case':':Tofile(18,0,id,con,fw);break;case';':Tofile(19,0,id,con,fw);break;case'{':Tofile(20,0,id,con,fw);break;case'}':Tofile(21,0,id,con,fw);break;default:error(fw);}}}intmain(){charc[100]="";FILE*fp,*fw;errno_terr;err=fopen_s(&fp,c,"r");if(err!=0){printf("Thefilewasnotopened\n");exit(0);}errno_terr1;err1=fopen_s(&fw,"","w");if(err1!=0){printf("Thefilewasnotopened\n");exit(0);}identifier*id=(identif