语法分析 实验报告

编译原理实验报告实验名称： 语法分析 实验类型： 设计性实验 指导教师： 蒋勇 专业班级： 软件1001班 姓名：李岳东 学号：20101557实验地点：东6A-319实验成绩：____________________________日期：2012年月日一、实验目的编译技术是理论与实践并重的课程，而其实验课要综合运用一、二年级所学的多门课程的内容，用来完成一个小型编译程序。从而巩固和加强对词法分析、语法分析、语义分析、代码生成和报错处理等理论的认识和理解；培养学生对完整系统的独立分析和设计的能力，进一步培养学生的独立编程能力。二、实验设计三、实验过程1)给定文法：（文法举例） EE+T｜T TT*F｜F F(E)｜i2)构造FIRST()集和FOLLOW()集表3-1FIRST()集和FOLLOW()集FIRSTFOLLOWE(，i#,+,)T(，i#,+,),*F(，i#,+,),* 四、实验结果 表4-1分析成功 表4-2分析失败 表4-3载入文件出错 流程图如下所示：五、附录：关键代码#include<iostream>#include<stdio.h>#include<ctype.h>#include<conio.h>#include<string.h>usingnamespacestd;intTESTparse();intprogram();intcompound_Stat();intstatement();intexpression_Stat();intexpression_r();intbool_expr();intadditive_expr();intterm();intfactor();intif_stat();intwhile_stat();intfor_stat();intwrite_stat();intread_stat();intdeclaration_stat();intdeclaration_list();intstatement_list();intcompound_stat();chartoken[20],token1[40];//token保存单词符号，token1保存单词值charScanout[300];//保存词法分析输出文件名FILE*fp;//用于指向输入输出文件的指针//语法分析程序intTESTparse(){intes=0;if((fp=fopen(Scanout,"r"))==NULL){printf("\n打开%s错误!\n",Scanout);es=10;}if(es==0)es=program();printf("=====语法分析结果!======\n");switch(es){case0:printf("语法分析成功!\n");break;case10:printf("打开文件%s失败!\n",Scanout);break;case1:printf("缺少{!\n");break;case2:printf("缺少}!\n");break;case3:printf("缺少标识符!\n");break;case4:printf("少分号!\n");break;case5:printf("缺少(!\n");break;case6:printf("缺少)!\n");break;case7:printf("缺少操作数!\n");break;}fclose(fp);return(es);}//<程序>::={<声明序列><语句序列>}//program::={<declaration_list><statement_list>}intprogram(){intes=0;fscanf(fp,"%s%s\n",token,token1);printf("%s%s\n",token,token1);if(strcmp(token,"{"))//判断是否'{'{es=1;return(es);}fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=declaration_list();if(es>0)return(es);es=statement_list();if(es>0)return(es);if(strcmp(token,"}"))//判断是否'}'{es=2;return(es);}return(es);}//<声明序列>::=<声明序列><声明语句>|<声明语句>//<declaration_list>::=//<declaration_list><declaration_stat>|<declaration_stat>//该成<declaration_list>::={<declaration_stat>}intdeclaration_list(){intes=0;while(strcmp(token,"int")==0){es=declaration_stat();if(es>0)return(es);}return(es);}//<声明语句>::=int<变量>；//<declaration_stat>::=intID;intdeclaration_stat(){intes=0;fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,"ID"))return(es=3);//不是标识符fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,";"))return(es=4);fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);return(es);}//<语句序列>::=<语句序列><语句>|<语句>//<statement_list>::=<statement_list><statement>|<statement>//改成<statement_list>::={<statement>}intstatement_list(){intes=0;while(strcmp(token,"}")){es=statement();if(es>0)return(es);}return(es);}//<语句>::=<if语句>|<while语句>|<for语句>|<read语句>//|<write语句>|<复合语句>|<表达式语句>//<statement>::=<if_stat>|<while_stat>|<for_stat>//|<compound_stat>|<expression_stat>intstatement(){intes=0;if(es==0&&strcmp(token,"if")==0)es=if_stat();//<IF语句>if(es==0&&strcmp(token,"while")==0)es=while_stat();//<while语句>if(es==0&&strcmp(token,"for")==0)es=for_stat();//<for语句>//可在此处添加do语句调用if(es==0&&strcmp(token,"read")==0)es=read_stat();//<read语句>if(es==0&&strcmp(token,"write")==0)es=write_stat();//<write语句>if(es==0&&strcmp(token,"{")==0)es=compound_stat();//<复合语句>if(es==0&&(strcmp(token,"ID")==0||strcmp(token,"NUM")==0||strcmp(token,"(")==0))es=expression_Stat();//<表达式语句>return(es);}//<IF语句>::=if(<表达式>)<语句>[else<语句>]//<IF_stat>::=if(<expr>)<statement>[else<statement>]intif_stat(){intes=0;//iffscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,"("))return(es=5);//少左括号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=expression_r();if(es>0)return(es);if(strcmp(token,")"))return(es=6);//少右括号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=statement();if(es>0)return(es);if(strcmp(token,"else")==0)//else部分处理{fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=statement();if(es>0)return(es);}return(es);}//<while语句>::=while(<表达式>)<语句>//<while_stat>::=while(<expr>)<statement>intwhile_stat(){intes=0;fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,"("))return(es=5);//少左括号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=expression_r();if(es>0)return(es);if(strcmp(token,")"))return(es=6);//少右括号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=statement();return(es);}//<for语句>::=for(<表达式>;<表达式>;<表达式>)<语句>//<for_stat>::=for(<expr>,<expr>,<expr>)<statement>intfor_stat(){intes=0;fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,"("))return(es=5);//少左括号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=expression_r();if(es>0)return(es);if(strcmp(token,";"))return(es=4);//少分号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=expression_r();if(es>0)return(es);if(strcmp(token,";"))return(es=4);//少分号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=expression_r();if(es>0)return(es);if(strcmp(token,")"))return(es=6);//少右括号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=statement();return(es);}//<write_语句>::=write<表达式>;//<write_stat>::=write<expression>;intwrite_stat(){intes=0;fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=expression_r();if(es>0)return(es);if(strcmp(token,";"))return(es=4);//少分号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);return(es);}//<read_语句>::=read<变量>;//<read_stat>::=readID;intread_stat(){intes=0;fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,"ID"))return(es=3);//少标识符fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);if(strcmp(token,";"))return(es=4);//少分号fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);return(es);}//<复合语句>::={<语句序列>}//<compound_stat>::={<statement_list>}intcompound_stat(){//复合语句函数intes=0;fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=statement_list();return(es);}//<表达式语句>::=<<表达式>;|;//<expression_stat>::=<expression>;|;intexpression_stat(){intes=0;if(strcmp(token,";")==0){fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);return(es);}es=expression_r();if(es>0)return(es);if(es==0&&strcmp(token,";")==0){fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);return(es);}else{es=4;return(es);//少分号}}//<表达式>::=<标识符>=<布尔表达式>|<布尔表达式>//<expr>::=ID=<bool_expr>|<bool_expr>intexpression_r(){intes=0,fileadd;chartoken2[20],token3[40];printf("aaaaaaaaaaa%s\n",token);if(strcmp(token,"ID")==0){fileadd=ftell(fp);//记住当前文件位置fscanf(fp,"%s%s\n",&token2,&token3);printf("%s%s\n",token2,token3);if(es>0)return(es);if(strcmp(token2,"=")==0)//'='{fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=bool_expr();}else{fseek(fp,fileadd,0);//若非'='则文件指针回到'='前的标识符printf("%s%s\n",token,token1);es=bool_expr();if(es>0)return(es);}}elsees=bool_expr();return(es);}//<布尔表达式>::=<算术表达式>|<算术表达式>(>|<|>=|<=|==|!=)<算术表达式>//<bool_expr>::=<additive_expr>//|<additive_expr>(>|<|>=|<=|==|!=)<additive_expr>intbool_expr(){intes=0;es=additive_expr();if(es>0)return(es);if(strcmp(token,">")==0||strcmp(token,">=")==0||strcmp(token,"<")==0||strcmp(token,"<=")==0||strcmp(token,"==")==0||strcmp(token,"!=")==0){fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=additive_expr();if(es>0)return(es);}return(es);}//<算术表达式>::=<项>{(+|-)<项>}//<additive_expr>::=<term>{(+|-)<term>}intadditive_expr(){intes=0;es=term();if(es>0)return(es);while(strcmp(token,"+")==0||strcmp(token,"-")==0){fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=term();if(es>0)return(es);}return(es);}//<项>::=<因子>{(*|/)<因子>}//<term>::=<factor>{(*|/)<factor>}intterm(){intes=0;es=factor();if(es>0)return(es);while(strcmp(token,"*")==0||strcmp(token,"/")==0){fscanf(fp,"%s%s\n",&token,&token1);printf("%s%s\n",token,token1);es=factor();if(es>0