计算机22班编译原理实验报告-语法分析

一、实验目的1、强化对系统综合工程实现能力的训练2、加强对语法分析原理、方法和基本实现技术的理解；二、实验内容：用C语言或者其他的高级语言作为宿主语言完成C语言的词法分析器的设计针对if语句的文法编写一个递归下降分析程序，输出结果为抽象语法树。注意，if语句文法中的表达式E采用四则运算表达式的文法；抽象语法树的格式自行设计，如果需要降低难度的话，也可用具体语法树而不用抽象语法树作为输出.三、实验过#include<iostream>#include<cstring>#include<cstdio>#include<fstream>#include<cmath>charprechar;//dangqianconstcharconstintid=3;intFILE*fp=fopen("C:\\Users\\hasee\\Desktop\\in.txt","r");/*文本方式打开FILE*fout=fopen("C:\\Users\\hasee\\Desktop\\out.txt","w+");/*文本方式写入class{intkind;intkind2;doublevalue;mword*next;mword*nlast;intwline;mword(intki,charna[20],boolen,double{if(kind==4||kind==5||kind==8)}void{for(int{if(strcmp(key[i],wname)==0)}}void{ elseif(kind==2)fprintf(fout,"<%0.0f,int>",value);elseif(kind==4)fprintf(fout,"<%s,operator>",wname);elseif(kind==5)fprintf(fout,"<%s,bound>",wname);elseif(kind==6)fprintf(fout,"<%s,key>",wname);elseif(kind==7)fprintf(fout,"<%s,speclchar>",wname);elseif(kind==100)fprintf(fout,"<%s,over>",wname);if(enter)fprintf(fout,"\n");}{c=fgetc(fp);returnc;}voidfgword(intki,charna[20],boolen,doubleva)//chuangjian{//if(prechar!='\n')en=0;last-if(p->kind==3)p-}voidcnum()//chang{intvis=0;//houvisweishixiaoshu{{if(vis){error[ernum]=tline;else}{ }}intif(vis)ki=1;//xiaoshudouble ki=2;//zhengshuint}voidcname()//biaoshi{while(prechar>='0'&&prechar<='9'||||prechar>='A'&&prechar<='Z'||{}}void //caozuo{charna[4];if(prechar=='=')elseif(na[0]=='-'&&prechar==na[0]){na[1]=prechar;prechar=mget();}elseif(na[0]=='+'&&prechar==na[0]){na[1]=prechar;prechar=mget();}elseif(na[0]=='|'&&prechar==na[0]){na[1]=prechar;prechar=mget();}elseif(na[0]=='&'&&prechar==na[0]){na[1]=prechar;prechar=mget();}}void //caozuo{charna[4];if(prechar=='=')elseif(na[0]=='-'&&prechar==na[0]){na[1]=prechar;prechar=mget();}elseif(na[0]=='+'&&prechar==na[0]){na[1]=prechar;prechar=mget();}elseif(na[0]=='|'&&prechar==na[0]){na[1]=prechar;prechar=mget();}elseif(na[0]=='&'&&prechar==na[0]){na[1]=prechar;prechar=mget();}}void{prechar=mget();}void //duihuanhangfude{}void{charna[5]="head";}void //shuruzhihouzuihoushanhou{//cout<<endl<<endl<<"Thereare"<<tline<<"//cout<<endl<<endl<<"Thereare"<<ernum<<"//for(intfclose(fp);/*关闭文件流*/}void{{}fprintf(fout,"\n\n所有对象:反响\n");{}}void{if(prechar>='0'&&prechar<='9')if(prechar>='a'&&prechar<='z'||prechar>='A'&&prechar<='Z')if(prechar=='|'||prechar=='&'||prechar=='!'){coprtlogic();continue;}if(prechar=='+'||prechar=='-'){coprt();continue;}if(prechar=='*'||prechar=='/'){coprt();continue;}if(prechar=='('||prechar==')'){cbound();continue;}if(prechar=='['||prechar==']'){cbound();continue;}if(prechar==':'||prechar==';'){cbound();continue;}if(prechar=='\n'){tline++;continue;}if(prechar=='\\'){cchar();continue;}if(feof(fp)){fgword(100,na,1,1);break;}}}{{case10:fprintf(fout,"L->H ||case12:fprintf(fout,"L1->--- case13:fprintf(fout,"H->I case14:fprintf(fout,"H1->&&I case15:fprintf(fout,"H1->--- case16:fprintf(fout,"H->(L case17:fprintf(fout,"I->J case18:{if(use->wname[0]=='!'){fprintf(fout,"J->! else{fprintf(fout,"J->---- case19:fprintf(fout,"K->E case20:fprintf(fout,"K1->--- case22:fprintf(fout,"K->(L case21:fprintf(fout,"K1->%s %s\n",use->wname,use-case30:fprintf(fout,"s0->S case31:fprintf(fout,"S1->S case33:fprintf(fout,"S->{SS1 {case34:fprintf(fout,"S->D case35:fprintf(fout,"D-> %s\n",use->wname,use-case36:fprintf(fout,"P-> %s\n",use-case37:fprintf(fout,"S->ID= %s%s\n",use->wname,use->next-case38:fprintf(fout,"S->if(L)SW if(\n");break;case39:fprintf(fout,"W->---- case40:fprintf(fout,"W->elseS case41:fprintf(fout,"S->while(L)S while(\n");break;case )case }case ;}}voidssinit(){}void //ZHIXIANGXIAYIGEDUI{use=use-}void{}voidvoid{if(sskind<=3)//{ %s\n",use-elseif(sskind==2)fprintf(fout,"A->id fprintf(fout,"A->id }elseif(ssnamefst=={fprintf(fout,"A->(E %s\n",use-{ %s\n",use-}else}}void{{}else{fprintf(fout,"F1->%sAF1 }{fprintf(fout,"F1->--}}void{{}else}void{{fprintf(fout,"E1->%sFE1 }elsefprintf(fout,"E1->- }void{{}}/////////////////////算术表达式分析voidlogicL();void{{}elseif{}{}}void{{}else{}}void{{}else{}{}}void{{}elseif(ssnamefst=='<'||ssnamefst=='>'||ssnamefst{}}void{{}elseif(ssnamefst=='<'||ssnamefst=='>'||ssnamefst{}{}}void{{}elseif(ssnamefst=='<'||ssnamefst=='>'||ssnamefst{}}void{{}elseif(sskind<=3||ssnamefst=='('||ssnamefst=='!'||ssnamefst=='&'||ssnamefst=='<'||ssnamefst=='>'||ssnamefst{}{}}void{{}elseif(sskind<=3||ssnamefst=='('||ssnamefst=='!'||ssnamefst=='&'||ssnamefst=='<'||ssnamefst=='>'||ssnamefst{}}voidvoid{{ }}void{{}else{}{}}void{if(sskind==3&&use->next-{{}elsesyerror();cout<<"S->id=L\n";}else{{cout<<"int/double"<<use-{}else}else}else{{{cout<<"if(L)";}else{syerror();}else}else{}else{cout<<"whlie(L)\n{\n";{{}else}else}}void{}void{use=head-}int{inta;return0;}S->S->{SS1{H1->---S->{SS1{L1->---S->if(L)Sif;L->HS->ID=hH->IL->HI->JH->IH->(LI->JE->FH->(LF->AE->FA->F->AF1->-A->4E1->-F1->-K1->---E1->-H1->---K1->---L1->---H1->---S->{SS1{ L1->---;jS->IDL->HLsS1->----}H->IW->elseI->JS->ID=fH->(LL->HE->FH->IF->AI->JA->7H->(LF1->-E->FE1->-K1->---F->AA->8F1->-F->AE1->