PL0编译原理课程设计PL0 + 理课程设计报告.docx

PL0.cpp#include pl0.h/*PL/0 语言编译程序，由江汉石油学院计算机系周云才根据清华大学出版社出版，*吕映芝，张素琴，蒋维杜编写的教材编译原理中第二章(PL/0编译程序的实现)*以及附录A中的代码改编而成。*代码版权由周云才拥有，使用者必须遵循以下约定：*可以免费使用此文件，但必须包含此声明。*可以修改、传播、打印、出版这里的源代码。*可以在任何软件工程中使用这里的源代码。* */ 错误字符串数组string PL0:errStr= ,error 0001: 常数说明中“=”写成“：=”,error 0002: 常数说明中的“=”后应为数字,error 0003: 常数说明中的标识符后应是“=”,error 0004: const,var,procedure后应为标识符,error 0005: 漏掉了,或;,error 0006: 过程说明后的符号不正确（应是语句开始符或过程开始符）,error 0007: 应是语句开始符,error 0008: 过程体内语句部分的后跟符不正确,error 0009: 程序皆为丢了句号.,error 0010: 语句之间漏了;,error 0011: 标识符没说明,error 0012: 赋值语句中，赋值号左部标识符属性应是变量,error 0013: 赋值语句左部标识符应是赋值号:=,error 0014: call后应为标识符,error 0015: call后标识符属性应为过程,error 0016: 条件语句中丢了then,error 0017: 丢了end或;,error 0018: while型循环语句中丢了do,error 0019: 语句后的标识符不正确,error 0020: 应为关系运算符,error 0021: 表达式内标识符属性不能是过程,error 0022: 表达式中漏掉了右括号),error 0023: 因子后的非法符号,error 0024: 表达式开始符不能是此符号,error 0025: 文件在不该结束的地方结束了,error 0026: 结束符出现在不该结束的地方,error 0027: ,error 0028: ,error 0029: ,error 0030: ,error 0031: 数越界,error 0032: read语句括号中标识符不是变量,error 0033: else附近错误 ,error 0034: repeat附近错误; / PL0构造函数PL0:PL0(char* source,char*destination)listswitch=true,sourceEnd=false;strcpy(word1,begin); / 初始化存储保留字strcpy(word2,call);strcpy(word3,const); strcpy(word4,do);strcpy(word5,else);strcpy(word6,end);strcpy(word7,if);strcpy(word8,odd);strcpy(word9,procedure);strcpy(word10,read);strcpy(word11,repeat);strcpy(word12,then);strcpy(word13,until);strcpy(word14,var);strcpy(word15,while);strcpy(word16,write);wsym1= BEGINSYM; wsym2= CALLSYM; / 初始化保留字表中每一个保留字对应的symbol类型 wsym3= CONSTSYM; wsym4= DOSYM;wsym5= ELSESYM; wsym6= ENDSYM;wsym7= IFSYM; wsym8= ODDSYM;wsym9= PROCSYM; wsym10= READSYM; wsym11= REPEATSYM; wsym12= THENSYM;wsym13= UNTILSYM; wsym14= VARSYM; wsym15= WHILESYM; wsym16= WRITESYM; memset(code,0,sizeof(code);memset(ssym,0,100*sizeof(symbol);memset(table,0,sizeof(table);memset(line,0,sizeof(line);ssym+= PLUS; / 初始化一些符号对应的symbol类型表ssym-= MINUS;ssym*= TIMES;ssym/= SLASH;ssym(= LPAREN;ssym)= RPAREN;ssym= EQL;ssym,= COMMA;ssym.= PERIOD;ssym#= NEQ;ssym= GTR;ssym;= SEMICOLON;strcpy(mnemonicLIT, lit ); / 初始化类PCODE指令助记符表 strcpy(mnemonicOPR, opr );strcpy(mnemonicLOD, lod );strcpy(mnemonicSTO, sto );strcpy(mnemonicCAL, cal );strcpy(mnemonicINT, int );strcpy(mnemonicJMP, jmp );strcpy(mnemonicJPC, jpc );declbegsys.insert(CONSTSYM),declbegsys.insert(VARSYM),declbegsys.insert(PROCSYM); / 初始化声明开始符号集合 statbegsys.insert(BEGINSYM),statbegsys.insert(CALLSYM),statbegsys.insert(IFSYM),statbegsys.insert(WHILESYM); / 初始化表达式开始符号集合facbegsys.insert(IDENT),facbegsys.insert(NUMBER),facbegsys.insert(LPAREN); / 初始化项开始符号集合err= 0;cc= 0; / 行缓冲区指针cx= 0; / 代码分配指针，代码生成模块总在cx所指位置生成新的代码 ll= 0; / 行缓冲区长度ch= ; / last character read kk= al; / 引入此变量是出于程序性能考虑codeNo=0; / code line no.fin=fopen(source,r);fout=fopen(destination,w);/ 出错处理，打印出错位置和出错代码void PL0:error(int n)char s10;sprintf(s,第 %d 行:,codeNo);errorString.push_back(s+errStrn);err= err+1;/error count/error end/ 词法分析，读取一个单词 void PL0:getsym()if(sourceEnd)return;int i,j,k;while (ch = |ch=9)getch(); / cls space and tabif(isalpha(ch) / id or reserved wordk=0;memset(a,0,al+1);/ 检测一个单词长度doif (k = kk)kk = k;elsedoakk= ;kk= kk-1;while(kk k);strcpy(id,a);i= 1;j= norw;/ 判断是否是关键字（二分搜索）dok= (i+j) / 2;if(strcmp(id, wordk)=0)i= k+1;while(i j)sym= wsymk;elsesym= IDENT;else if(isdigit(ch) / numberk= 0;num= 0;sym= NUMBER;donum= 10 * num + ch - 0;k= k+1;getch();while(isdigit(ch);if(k nmax)error(30);else if (ch = :)getch();if( ch = =)sym= BECOMES;getch();elsesym= NUL;else if(ch = ) / extra stuff added to support )getch();if( ch = =)sym= GEQ;getch();elsesym= GTR;else / end of extra stuffsym= ssymch; / 其它符号的赋值getch();/ 漏掉空格，读取一个字符void PL0:getch()if(cc = ll)if(feof(fin)if(sym!=PERIOD)error(25);sourceEnd=true;return;cc= 0;fgets(line,lineLength,fin);codeNo+;ll=strlen(line);if(linell-1=10) ll-;ch= linecc;cc= cc+1;/ 生成目标代码，并送入目标程序区void PL0:gen(fct x,int y,int z)if (cx cxmax)coutlevmax)error(32);do if( sym = CONSTSYM) / 处理常量声明getsym();doconstdeclaration(tx,dx,lev);while (sym = COMMA)getsym();constdeclaration(tx,dx,lev);if (sym =SEMICOLON)getsym();elseerror(5);while(sym=IDENT);if( sym = VARSYM) / 处理变量声明getsym();dovardeclaration(tx,dx,lev);while( sym = COMMA)getsym();vardeclaration(tx,dx,lev);if( sym =SEMICOLON)getsym();elseerror(5);while(sym=IDENT);while( sym =PROCSYM) / 处理过程的声明getsym();if (sym =IDENT)enter(PROCEDURE,tx,dx,lev);getsym();elseerror(4);if( sym =SEMICOLON)getsym();elseerror(5);symset tmp = fsys;tmp.insert(SEMICOLON);block(lev+1,tx,tmp);if (sym = SEMICOLON)getsym();symset tmp = statbegsys;for(int i= IDENT;i=PROCSYM;i+)tmp.insert(symbol)i);test(tmp,fsys,6);elseerror(5);symset tmp=statbegsys;tmp.insert(IDENT);test(tmp,declbegsys,7);while(declbegsys.find(sym)!=declbegsys.end();codetabletx0.other.inOther.adr.a= cx;tabletx0.other.inOther.adr= cx; / start adr of codetabletx0.other.inOther.size=dx;cx0= cx;gen(INT,0,dx);symset tmp=statbegsys;for(int i=SEMICOLON;i amax)error(31);num=0;tabletx.other.val=num;break;case VARIABLE:tabletx.other.inOther.level=lev;tabletx.other.inOther.adr=dx;dx+;break;case PROCEDURE:tabletx.other.inOther.level=lev;break;case ARRAY:tabletx.other.inOther.size = lev;break;/enter end/ 查找标示符在名字表中的位置 int PL0:position(alfa id,int tx)/find identifier id in tableint i;strcpy(, id);i= tx;while (strcmp(,id)!=0)i-;return i;/position end/ 常量定义处理void PL0:constdeclaration(int&tx,int&dx,int lev)if(sym = IDENT) getsym(); if(sym=EQL&sym=BECOMES) if( sym =BECOMES) error(1);getsym();if( sym = NUMBER)enter(CONSTANT,tx,dx,lev);getsym();else error(2); elseerror(3);else error(4);/ constdeclaration end/ 变量说明处理void PL0:vardeclaration(int&tx,int&dx,int lev)if( sym = IDENT)enter(VARIABLE,tx,dx,lev);getsym();elseerror(4);/vardeclaration end/ 数组说明处理void PL0:arraydeclaration(int&tx,int&dx,int lev) int upscript=0,downscript=0;getsym();if(sym = NUMBER | sym = CONSTSYM)if(num = 0)upscript = num;getsym();else error(32);if(sym = COMMA)getsym();elseerror(32);if(sym = NUMBER | sym = CONSTSYM)downscript = num;getsym();if(sym != RPAREN)error(32);elseenter(ARRAY,tx,dx,downscript+1);getsym();/ 列出目标代码清单void PL0:listcode(int cx0)/list code generated for this blockint i;if(listswitch)for (i= cx0;icx;i+) cout i mnemoniccodei.f codei.l codei.aendl;/ listcode end/ 语句部分处理 void PL0:statement(symset fsys,int tx,int lev)if(sourceEnd)return;int i,cx1,cx2;if(sym =IDENT)i= position(id,tx);if (i = 0)error(11);else if (tablei.kind!=VARIABLE)error(12);i= 0;getsym();if(sym =BECOMES)getsym();elseerror(13);expression(fsys,tx,lev);if(sym != SEMICOLON)error(10);if( i!= 0)gen(STO,lev-tablei.other.inOther.level,tablei.other.inOther.adr);else if( sym = READSYM)getsym();if( sym!=LPAREN)error(34);elsedogetsym();if (sym=IDENT)i=position(id,tx);elsei=0;if( i=0 )error(35);elsegen(OPR,0,16);gen(STO,lev-tablei.other.inOther.level,tablei.other.inOther.adr);getsym();while(sym = COMMA);if (sym != RPAREN)error(33);while (fsys.find(sym)!=fsys.end() getsym();else getsym();else if( sym = WRITESYM )getsym();if (sym=LPAREN)dogetsym();symset tmp=fsys;for(int t=RPAREN;t=COMMA;t+)tmp.insert(symbol)t);expression(tmp,tx,lev);gen(OPR,0,14);while(sym=COMMA);if (sym!=RPAREN)error(33);elsegetsym();gen(OPR,0,15);else if( sym =CALLSYM)getsym();if( sym!=IDENT)error(14);elsei= position(id,tx);if (i = 0)error(11);else if (tablei.kind = PROCEDURE)gen(CAL,lev-tablei.other.inOther.level,tablei.other.inOther.adr);elseerror(15);getsym();else if( sym =IFSYM)getsym();symset tmp=fsys;for(int i = THENSYM;i= DOSYM;i+)tmp.insert(symbol)i);condition(tmp,tx,lev);if( sym = THENSYM)getsym();elseerror(16);cx1= cx;gen(JPC,0,0);tmp.insert(ELSESYM);statement(tmp,tx,lev);getsym();codecx1.a= cx;if(sym = ELSESYM) getsym(); cx2=cx; gen(JMP,0,0); codecx1.a=cx; statement(fsys,tx,lev); codecx2.a=cx;else if( sym =BEGINSYM)getsym();symset tmp=fsys;for(int i=SEMICOLON;i=ENDSYM;i+)tmp.insert(symbol)i);statement(tmp,tx,lev);tmp=statbegsys;tmp.insert(SEMICOLON);while( tmp.find(sym)!=tmp.end()if(sourceEnd)return;if (sym =SEMICOLON|sym =ENDSYM)getsym();else if(sym=PERIOD)error(26);getsym();elseerror(10);tmp=fsys;for(i=SEMICOLON;i=ENDSYM;i+)tmp.insert(symbol)i);if(sourceEnd)return;if(sym=ENDSYM)break;statement(tmp,tx,lev);if( sym =ENDSYM)getsym();else if(!sourceEnd)error(17);else if(sym =WHILESYM)cx1= cx; / 记下当前代码分配位置，这是while循环的开始位置getsym();symset tmp=fsys;tmp.insert(DOSYM);condition(tmp,tx,lev); cx2= cx; / 记下当前代码分配位置，这是while的do中的语句的开始位置gen(JPC,0,0);if(sym =DOSYM)getsym();elseerror(18);statement(fsys,tx,lev);gen(JMP,0,cx1);codecx2.a= cx;else if(sym = REPEATSYM)symset temp1, temp2;temp1= fsys,temp1.insert(SEMICOLON),temp1.insert(UNTILSYM);cx1= cx;getsym();statement(temp1,tx,lev);temp2 = statbegsys;temp2.insert(SEMICOLON);while(temp2.find(sym) != temp2.end()if(sym = SEMICOLON)getsym();else error(34);statement(temp1,tx,lev);if(sym = UNTILSYM)getsym();condition(fsys,tx,lev);gen(JPC,0,cx1);elseerror(34); symset setT;test(fsys,setT,19);/statement end/ 表达式处理 void PL0:expression(symset fsys,int tx,int lev)symbol addop;symset tmp=fsys;for(int t=PLUS;t=PLUS&sym=PLUS&sym=MINUS)addop= sym;getsym();term(tmp,tx,lev);if (addop =PLUS)gen(OPR,0,2);elsegen(OPR,0,3);/ expression end/ 项处理void PL0:term(symset fsys,int tx,int lev)if(sourceEnd)return;symbol mulop;symset tmp=fsys;for(int t=TIMES;t=TIMES & symamax)error(31);num= 0;gen(LIT,0,num);getsym();else if( sym =LPAREN)getsym();symset tmp=fsys;tmp.insert(RPAREN);expression(tmp,tx,lev);if (sym = RPAREN)getsym();elseerror(22);test(fsys,facbegsys,23);/factor end/ 条件处理void PL0:condition(symset fsys,int tx,int lev)symbol relop;symset tmp=fsys;tmp.insert(EQL),tmp.insert(NEQ),tmp.insert(LSS),tmp.insert(LEQ),tmp.insert(GTR),tmp.insert(GEQ); if( sym = ODDSYM)getsym();expression(fsys,tx,lev);gen(OPR,0,6);elseexpression(tmp,tx,lev);if(tmp.find(sym)=tmp.end()error(20);elserelop= sym;getsym();expression(fsys,tx,lev);switch(relop)case EQL: gen(OPR,0,8);break;case NEQ: gen(OPR,0,9);break;case LSS: gen(OPR,0,10);break;case GEQ: gen(OPR,0,11);break;case GTR: gen(OPR,0,12);break;case LEQ: gen(OPR,0,13);break;/condition end/ 对目标代码的解释执行程序 void PL0:interpret()int err1=errorString.size();if(err10)cout存在%d个错误:err1endl;for(int i=0;ierr1;i+)couterrorStringiendl;/return;const int stacksize = 500;int p=0,b=1,t=0;/program-,base-,topstack-registersinstruction i;/ instruction registerint sstacksize+1=0;/ datastorecout Start PL/0n;doi= codep;p= p+1;switch(i.f)case LIT:t= t+1;st= i.a;break;case OPR:switch(i.a) /operatorcase 0:/ returnt= b-1; p= st+3; b= st+2;break;case 1:st= -st;break;case 2:t= t-1;st= st+st+1;break;case 3:t= t-1;st= st-st+1;break;case 4:t= t-1;st= st*st+1;break;case 5:t= t-1;st= st / st+1;break;case 6:if(st%2)st=1;elsest=0;break;case 8:t= t-1;if(st=st+1)st=1;elsest=0;break;case 9:t= t-1;if(st=st+1)st=0;elsest=1;break;case 10:t= t-1;if(st=st+1)st= 1;elsest=0;break;case 12:t= t-1;if(stst+1)st= 1;elsest=0;break;case 13:t= t-1;if(st=st+1)st= 1;elsest=0;b