词法分析和语法分析设计编译器编译原理课程设计.doc

【精品文档】如有侵权，请联系网站删除，仅供学习与交流词法分析和语法分析设计编译器编译原理课程设计.精品文档.编译原理课程设计报告课题名称： C- Minus词法分析和语法分析设计 提交文档学生姓名： X X X 提交文档学生学号： XXXXXXXXXX 同组 成 员 名 单： X X X 指导 教 师 姓 名： X X 指导教师评阅成绩： 指导教师评阅意见： 提交报告时间：2015年6月10日1. 课程设计目标实验建立C-编译器。只含有扫描程序（scanner）和语法分析（parser）部分。2. 分析与设计C-编译器设计的整体框架，本实验实现扫描处理和语法分析程序（图中粗黑部分）。 2.1 、扫描程序scanner部分2.1.1系统设计思想设计思想：根据DFA图用switch-case结构实现状态转换。 惯用词法： 语言的关键字：else if int return void while 专用符号：+ - * / < <= > >= = != = ; , ( ) /* */ 其他标记是ID和NUM，通过下列正则表达式定义： ID = letter letter* NUM = digit digit* letter = a|.|z|A|.|Z digit = 0|.|9大写和小写字母是有区别的 空格由空白、换行符和制表符组成。空格通常被忽略，除了它必须分开ID、NUM关键字。 注释用通常的C语言符号/ * . . . * /围起来。注释可以放在任何空白出现的位置(即注释不能放在标记内)上，且可以超过一行。注释不能嵌套说明：当输入的字符使DFA到达接受状态的时候，则可以确定一个单词了。初始状态设置为START，当需要得到下一个token时，取得次token的第一个字符，并且按照DFA与对此字符的类型分析，转换状态。重复此步骤，直到DONE为止，输出token类型。当字符为“/”时，状态转换为SLAH再判断下一个字符，如果为“*”则继续转到INCOMMENT，最后以“*”时转到ENDCOMMENT状态，表明是注释，如果其他的则是字符停滞于当前字符，并且输出“/”。2.1.2程序流程图2.1.3 各文件或函数的设计说明扫描程序用到:scanner.h,scanner.cppØ scanner.h：声明词法状态，词法分析/DFA中的状态typedef enumSTART = 1, INNUM, INID, INDBSYM, DONE DFAState;/定义的Token的类型(31种)，分别对应于else、if、int、return、void、while、+、-、*、/、<、<=、>、>=、=、!=、=、;、,、(、)、/*、*/、num、id、错误、结束typedef enumELSE = 1,IF,INT,RETURN,VOID,WHILE,PLUS,MINUS,TIMES,OVER,LT,LEQ,GT,GEQ,EQ,NEQ,ASSIGN,SEMI,COMMA,LPAREN,RPAREN,LMBRACKET,RMBRACKET,LBBRACKET,RBBRACKET,LCOMMENT,RCOMMENT,NUM,ID,ERROR,ENDFILE TokenType;/定义的Token结构体，包括类型、对应的串、所在代码的行号struct TokenTokenType tokenType;string tokenString;int lineNo;/每种TokenType对应的串，如tokenTypeStringELSE="ELSE"const string tokenTypeString32 = "OTHER", "ELSE", "IF", "INT", "RETURN", "VOID", "WHILE", "PLUS", "MINUS", "TIMES", "OVER", "LT", "LEQ", "GT", "GEQ", "EQ", "NEQ", "ASSIGN", "SEMI", "COMMA", "LPAREN", "RPAREN", "LMBRACKET", "RMBRACKET", "LBBRACKET", "RBBRACKET", "LCOMMENT", "RCOMMENT", "NUM", "ID", "ERROR", "ENDFILE"class Scanner:定义scanner.cpp中函数Ø scanner.cpp文件函数说明void Scanner : scan()：设置输出结果界面以及设置各种输出状态。if(scanSuccess=false)cout<<"词法分析出错！"<<endl;elsecout<<"词法分析成功了！"<<endl;printToken();/*输出Token到文件Token.txt中*/正在删除注释void Scanner : deleteComments()TokenType Scanner : returnTokenType(string s)/返回Token的类型DFAState Scanner : charType(char c)/返回字符的类型typedef enum ENDFILE,ERROR, IF,ELSE,INT,RETURN,VOID,WHILE, /关键字ID,NUM, ASSIGN,PLUS,MINUS,TIMES,OVER,EQ,UEQ,LT,LPAREN,RPAREN,SEMI,BT,LQ,BQ, DOU,LZGH,RZGH,LDGH,RDGH,/特殊字符：= + - * / = != < 等 TokenType;2.1.4 测试程序说明根据附录A后面的例子，程序输入两个整数，计算并打印出它们的最大公因子，保存为a.txt。/* A program to perform Eucild's Algorithm to compute gcd. */int gcd (int u, int v) if (v=0) return u; else return gcd(v,u-u/v*v); /* u-u/v*v= u mod v */void main(void) int x; int y; x=input(); y=input(); output(gcd(x,y);2.2、语法分析parse部分2.2.1系统设计思想设计思想：parser用递归下降分析方法实现,通过调用词法分析函数getToken实现语法分析。根据C-语言的规则，得出BNF语法如下： 1.program->declaration-list 2.declaration-list->declaration-list declaration | declaration 3.declaration->var-declaration|fun-declaration 4.var-declaration->type-specifier ID;|type-specfier IDNUM 5.type-specifier->int|void 6.fun-specifier ID(parans) compound-stmt 7.params->params-list|void 8.param-list->param-list,param|param 9.param->type-specifier ID|type-specifier ID pound-stmt->local-declarations statement-list 11.local-declarations->local-declarations var-declaration|empty 12.statement-list->statement-list statement|empty 13.statement->expression-stmt|compound-stmt|selection-stmt|iteration-stmt|return-stmt 14.expression-stmt->expression;|; 15.selection-stmt->if(expression)statement|if(expression)statement else statement 16.iteration-stmt->while(expression)statement 17.return-stmt->return ;|return expression; 18.expression->var=expression|simple-expression 19.var->ID|IDexpression 20.simple-expression->additive-expression relop additive-expression|additive-expression 21.relop-><=|<|>|>=|=|!= 22.additive-expression->additive-expression addop term|term 23.addop->+|- 24.term->term mulop factor|factor 25.mulop->*|/ 26.factor->(expression)|var|call|NUM 27.call->ID(args) 28.args->arg-list|empty 29.arg-list->arg-list,expression|expression2.1.2语法分析程序流程图 2.1.3 各文件或函数的设计说明语法分析程序包括：parser.cpp,parser.hØ parser.cpp： Parser : Parser()/界面设计 Token Parser : getToken()/获取scanner中保存在TokenList数组中的Token，并且每次获取完之后数组下标指向下一个void Parser : syntaxError(string s)/出错处理void Parser : match(TokenType ex)/匹配出错TreeNode * Parser : declaration(void)/类型匹配错误TreeNode * Parser : param_list(TreeNode * k)/k可能是已经被取出来的VoidK，但又不是(void)类型的参数列表，所以一直传到param中去，作为其一个子节点Ø parse.h：对parse.c的函数声明 /19种节点类型，分别表示int、id、void、数值、变量声明、数组声明、函数声明、函数声明参数列表、函数声明参数、复合语句体、if、while、return、赋值、运算、数组元素、函数调用、函数调用参数列表、未知节点typedef enum IntK, IdK, VoidK, ConstK, Var_DeclK, Arry_DeclK, FunK, ParamsK, ParamK, CompK, Selection_StmtK, Iteration_StmtK, Return_StmtK, AssignK, OpK, Arry_ElemK, CallK, ArgsK, UnkownK Nodekind;typedef enum Void,Integer ExpType;ofstream fout_Tree("tokenTree.txt");/输出语法树到文件/treeNode定义 包括子节点、兄弟节点、所处行号、节点类型、属性、表达式返回类型typedef struct treeNode TreeNode * newNode(Nodekind k);/根据节点类型新建节点TreeNode * declaration_list(void);TreeNode * declaration(void);TreeNode * params(void);TreeNode * param_list(TreeNode * k);TreeNode * param(TreeNode * k);TreeNode * compound_stmt(void);TreeNode * local_declaration(void);TreeNode * statement_list(void);TreeNode * statement(void);TreeNode * expression_stmt(void);TreeNode * selection_stmt(void);TreeNode * iteration_stmt(void);TreeNode * return_stmt(void);TreeNode * expression(void);TreeNode * var(void);TreeNode * simple_expression(TreeNode * k);TreeNode * additive_expression(TreeNode * k);TreeNode * term(TreeNode * k);TreeNode * factor(TreeNode * k);TreeNode * call(TreeNode * k);TreeNode * args(void);2.1.4 测试程序说明根据附录A后面的例子，程序输入两个整数，计算并打印出它们的最大公因子，保存为a.txt。/* A program to perform Eucild's Algorithm to compute gcd. */int gcd (int u, int v) if (v=0) return u; else return gcd(v,u-u/v*v); /* u-u/v*v= u mod v */void main(void) int x; int y; x=input(); y=input(); output(gcd(x,y);3. 程序代码实现按文件列出主要程序代码, 添加必要的注释.Scanner.cpp:#include <cstdlib>#include <iostream>#include <fstream>#include <string>#include "scanner.h"#include<vector>using namespace std;Name: 词法分析器Copyright: Author: XXXDate: 19-05-14 12:00Description: 提取出tokenScanner : Scanner()scanSuccess = true;charIndex = 0;str = ""commentFlag = true;sourseString = ""lineCount = 0;void Scanner : scan()cout<<"开始词法分析."<<endl;bool doubleSym = false;getSourseStringFromFile("sourseFile.txt");int state = START;lineCount = 0;char ch;while(state<6)ch = getNextChar();if('0'=ch)Token t;t.lineNo = lineCount;t.tokenString = ""t.tokenType = ENDFILE;tokenList.push_back(t);break;if(START=state)/初始状态和空格state = charType(ch);if(state!=START)str += ch;else if(INNUM=state)/digitstate = charType(ch);if(state!=INNUM)state = DONE;elsestr += ch;else if(INID=state)/letterstate = charType(ch);if(state!=INID)state = DONE;elsestr += ch;else if(INDBSYM=state)/除了<>=!之外的各种符号if('='=ch)str += ch;doubleSym = true;elsedoubleSym = false;state = DONE;if(DONE=state)/接收状态int tp = 0;if('n'=ch)tp = 1;Token t;t.lineNo = lineCount-tp;t.tokenString = str;t.tokenType = returnTokenType(str);tokenList.push_back(t);if(ERROR=t.tokenType)scanSuccess = false;int lastState = charType(strstr.length()-1);if(lastState=INNUM | lastState=INID | (lastState=INDBSYM && doubleSym=false)backToLastChar();str = ""state = START;if(doubleSym=true)doubleSym = false;if(scanSuccess=false)cout<<"词法分析出错！"<<endl;elsecout<<"词法分析成功了！"<<endl;printToken();/输出Token到文件Token.txt中Token Scanner : getTokenAt(int tokenIndex)Token token;token.lineNo = lineCount;token.tokenString = ""token.tokenType = ENDFILE;if(tokenIndex<tokenList.size()token = tokenList.at(tokenIndex+);return token;void Scanner : getSourseStringFromFile(string path)ifstream fin(path.c_str();string temp; sourseString = ""while(getline(fin,temp)sourseString += temp;sourseString += 'n'fin.close();charIndex = 0;void Scanner : deleteComments()cout<<"正在删除注释."<<endl;ofstream fout_Sourse("sourseFile.txt");int state = 1;char ch;while(state<6)ch = getNextChar();if('0'=ch)/文件结束break;if(1=state)if('/'=ch)state = 2;elsestate = 1;fout_Sourse<<ch;else if(2=state)if('*'=ch)state = 3;commentFlag = false;elsestate = 1;fout_Sourse<<"/"<<ch;else if(3=state)if('*'=ch)state = 4;elsestate = 3;else if(4=state)if('*'=ch)state = 4;else if('/'=ch)state = 5;elsestate = 3;if(5=state)/结束状态，处理commentFlag = true;state = 1;if(!commentFlag)cout<<"注释错误，没有结束符！"<<endl;scanSuccess = false;elsecout<<"注释已经成功删除！"<<endl;TokenType Scanner : returnTokenType(string s)/返回Token的类型TokenType t;if(s="else")t = ELSE;else if(s="if")t = IF;else if(s="int")t = INT;else if(s="return")t = RETURN;else if(s="void")t = VOID;else if(s="while")t = WHILE;else if(s="+")t = PLUS;else if(s="-")t = MINUS;else if(s="*")t = TIMES;else if(s="/")t = OVER;else if(s="<")t = LT;else if(s="<=")t = LEQ;else if(s=">")t = GT;else if(s=">=")t = GEQ;else if(s="=")t = EQ;else if(s="!=")t = NEQ;else if(s="=")t = ASSIGN;else if(s="")t = SEMI;else if(s=",")t = COMMA;else if(s="(")t = LPAREN;else if(s=")")t = RPAREN;else if(s="")t = LMBRACKET;else if(s="")t = RMBRACKET;else if(s="")t = LBBRACKET;else if(s="")t = RBBRACKET;else if(s="/*")t = LCOMMENT;else if(s="*/")t = RCOMMENT;else if(2=charType(ss.length()-1)t = NUM;else if(3=charType(ss.length()-1)t = ID;elset = ERROR;return t;DFAState Scanner : charType(char c)/返回字符的类型if(' '=c | 'n'=c | 't'=c |'r'=c)return START; else if(c>='0'&&c<='9')return INNUM; else if(c>='A'&&c<='Z')|(c>='a'&&c<='z')return INID;else if(c='<' | c='>' | c='=' | c='!')return INDBSYM; elsereturn DONE;char Scanner : getNextChar()if(charIndex<sourseString.length()char ch = sourseStringcharIndex;charIndex+;if('n'=ch)lineCount+;return ch;elsereturn '0'void Scanner : backToLastChar()if(charIndex>0)char ch = sourseStringcharIndex-1;charIndex-;if('n'=ch)lineCount-;void Scanner : printToken()ofstream fout_Token("Token.txt");ifstream fin("sourseFile.txt");string temp; int lineCount = 0;int index = 0;while(getline(fin,temp)fout_Token<<lineCount<<": "fout_Token<<temp<<endl;while(index<tokenList.size()Token t = tokenList.at(index);if(lineCount=t.lineNo)fout_Token<<" "<<lineCount<<": "index+;int width = 10;string headS = " "if(t.tokenType>=1&&t.tokenType<=6)/关键字string tp = ""for(int i = 0; i<width-t.tokenString.length(); i+)tp += " "fout_Token<<"keyWord："<<headS<<t.tokenString<<" "<<tp<<""<<tokenTypeStringt.tokenType<<""<<endl;else if(t.tokenType>=7&&t.tokenType<=27)/符号string tp = ""for(int i = 0; i<width-t.tokenString.length(); i+)tp += " "fout_Token<<"symbols："<<headS<<t.tokenString<<" "<<tp<<""<<tokenTypeStringt.tokenType<<""<<endl;else if(t.tokenType=28)/NUMstring tp = ""for(int i = 0; i<width-t.tokenString.length(); i+)tp += " "fout_Token<<" NUM："<<headS<<t.tokenString<<" "<<tp<<""<<tokenTypeStringt.tokenType<<""<<endl;else if(t.tokenType=29)/IDstring tp = ""for(int i = 0; i<width-t.tokenString.length(); i+)tp += " "fout_Token<<" ID："<<headS<<t.tokenString<<" "<<tp<<""<<tokenTypeStringt.tokenType<<""<<endl;else if(t.tokenType=30)/错误string tp = ""for(int i = 0; i<width-t.tokenString.length(); i+)tp += " "fout_Token<<" error："<<headS<<t.tokenString<<" "<<tp<<""<<tokenTypeStringt.tokenType<<""<<endl;else if(t.tokenType=ENDFILE)/结束fout_Token<<" "<<lineCount<<": "fout_Token<<t.tokenString<<" "<<""<<tokenTypeStringt.tokenType<<""<<endl;if(lineCount<t.lineNo)break;lineCount+;fin.close();fout_Token.close();scanner.h:#include<string>#include<vector>using namespace std;/定义的Token的类型(31种)，分别对应于else、if、int、return、void、while、+、-、*、/、<、<=、>、>=、=、!=、=、;、,、(、)、/*、*/、num、id、错误、结束typedef enumELSE = 1,IF,INT,RETURN,VOID,WHILE,PLUS,MINUS,TIMES,OVER,LT,LEQ,GT,GEQ,EQ,NEQ,ASSIGN,SEMI,COMMA,LPAREN,RPAREN,LMBRACKET,RMBRACKET,LBBRACKET,RBBRACKET,LCOMMENT,RCOMMENT,NUM,ID,ERROR,ENDFILE TokenType;typedef enumSTART = 1, INNUM, INID, INDBSYM, DONE DFAState;/定义的Token结构体，包括类型、对应的串、所在代码的行号struct TokenTokenType tokenType;string tokenString;int lineNo;/每种TokenType对应的串，如tokenTypeStringELSE="ELSE"const string tokenTypeString32 = "OTHER", "ELSE", "IF", "INT", "RETURN", "VOID", "WHILE", "PLUS", "MINUS", "TIMES", "OVER", "LT", "LEQ", "GT", "GEQ", "EQ", "NEQ", "ASSIGN", "SEMI", "COMMA", "LPAREN", "RPAREN", "LMBRACKET", "RMBRACKET", "LBBRACKET", "RBBRACKET", "LCOMMENT", "RCOMMENT", "NUM", "ID", "ERROR", "ENDFILE"class Scannerpublic:bool scanSuccess;/词法分析是否成功的标志void getSourseStringFromFile(string s);/通过提供的文件名获取源代码void deleteComments();/删除注释void scan();/词法分析，将分析的Token放在tokenList数组中Scanner();Token getTokenAt(int);/根据下标从tokenList数组中获取Tokenprivate:DFAState charType(char);/返回字符的类型，如：空格2：数字3：字母等char getNextChar();/获取到下一个字符void backToLastChar();TokenType returnTokenType(string s);/根据字符串返回Token类型void printToken();/将词法分析好的Token输出到文件Token.txt中string sourseString;/获取源代码的字符串