編譯原理詞法分析器實驗報告最終

1、 學院（系）名稱：計算機工程系姓名學號專業(yè)班級實驗項目實驗一：詞法分析課程名稱編譯原理課程代碼0310243實驗時間 2013年 4月28 日 第 1、2 節(jié) 2013年 5月 7 日 第1 、2 節(jié)實驗地點第一教學樓1508批改意見成績教師簽字： 實驗內容： 實現(xiàn)標準C語言詞法分析器實驗目的：1掌握程序設計語言詞法分析的設計方法；2掌握DFA的設計與使用方法；3掌握正規(guī)式到有限自動機的構造方法；實驗要求：1單詞種別編碼要求 基本字、運算符、界符：一符一種； 標識符：統(tǒng)一為一種； 常量：按類型編碼；2詞法分析工作過程中建立符號表、常量表，并以文本文件形式輸出；3詞法分析的最后結果以文本文件形式

2、輸出；4完成對所設計詞法分析器的功能測試，并給出測試數(shù)據(jù)和實驗結果；5為增加程序可讀性，請在程序中進行適當注釋說明；6整理上機步驟，總結經驗和體會；7認真完成并按時提交實驗報告。實驗步驟：1.基本思想：從源程序中依次讀入字符并解析,與關鍵字、運算符、結束符進行比較，得出其中的關鍵字，并將它存入到數(shù)組中去。2.程序源代碼：#include<stdio.h>#include<cstring>#include<stdlib.h>#define MaxSize1 17/關鍵字的個數(shù)#define MaxSize2 20/運算符的個數(shù)#define MaxSize3

3、4/結束符的個數(shù)/數(shù)據(jù)結構struct TNodechar value20;/存放標識符的值int number; /存放標識符的種別碼char description20;/描述KeyWordsMaxSize1,OperationMaxSize2,EndOperationMaxSize3;/存放關鍵字的數(shù)組char *WordsBuffMaxSize1="const","long","float","double","void","main","if",

4、"else","then","break","int","char","include","for","while","printf","scanf"/存放運算符的數(shù)組char *OperationBuffMaxSize2="+","-","*","/","+=","-=",&q

5、uot;*=","+","-","<","<=",">",">=","<>","=","(",")","#","",""char EndOperationBuffMaxSize3=' ','','n','t'/存放詞法分析程序輸出

6、的結果TNode Table1500;TNode Variable100;/標識符表TNode Const100;/關鍵字數(shù)組初始化void inputKeyWords(char * buff,int size)/關鍵字編碼從1-sizefor(int i=0;i<size;i+)strcpy(KeyWordsi.value,buffi);KeyWordsi.number=i+1;strcpy(KeyWordsi.description,"關鍵字");/運算符數(shù)組初始化void inputOperation(char * buff,int size)/運算符編碼從50

7、-(50+size)for(int i=0;i<size;i+)strcpy(Operationi.value,buffi);Operationi.number=i+50;strcpy(Operationi.description,"運算符");/結束符數(shù)組初始化void inputEndOperation(char buff,int size)/結束符編碼從100-(100+size);for(int i=0;i<size;i+)EndOperationi.value0=buffi;EndOperationi.value1='0'EndOper

8、ationi.number=i+100;strcpy(EndOperationi.description,"結束符");/輸出數(shù)據(jù)結構數(shù)組中的信息void outputInfo(TNode a,int size)for(int i=0;i<size;i+)printf("(%d",ai.number);printf("t");printf("%s)",ai.value);printf("t");printf(ai.description);printf("n");voi

9、d outInfoToFile(TNode a,int size,FILE *out)/將詞法分析程序的結果輸出到文件中去for(int i=0;i<size;i+)fprintf(out,"(%d",ai.number);fprintf(out,"t");fprintf(out,"%s)",ai.value);fprintf(out,"t");fprintf(out,ai.description);fprintf(out,"n");/從文件中讀取一個字符/返回文件中讀取的字符char g

10、etChar(FILE *fp)char ch=fgetc(fp);return ch;/判讀是否是運算符int isOperation(char a)/返回i表示是運算符在運算符數(shù)組中的位置/返回-1表示不是運算符int result;for(int i=0;i<MaxSize2;i+)result=strcmp(a,Operationi.value);if(result=0)return i;break;return -1;/判讀是否是關鍵字int isKeyWords(char a)/返回i表示在關鍵字表中的位置/返回-1表示不是關鍵字int result;for(int i=0;

11、i<MaxSize1;i+)result=strcmp(a,KeyWordsi.value);if(result=0)return i;break;return -1;/判讀是否是結束符int isEndOperation(char a)/返回i表示是結束符在結束符表中的位置/返回-1表示不是結束符for(int i=0;i<MaxSize3;i+)if(a=EndOperationi.value0)return i;break;return -1;/判讀是否是字符int isChar(char a)/返回1表示是字符/返回0表示不是字符if(a>='a'&a

12、mp;&a<='z')return 1;else if(a>'A'&&a<='Z')return 1;elsereturn 0;/判讀是否是數(shù)字int isDigit(char a)/返回1表示是數(shù)字/返回0表示不是數(shù)字if(a>='0'&&a<='9')return 1;elsereturn 0;int count=0;/記錄結果表中的關鍵字及運算符等表項個數(shù)，用于返回int count1=0;/記錄標識符的表項個數(shù)int count2=0;/

13、記錄常量的表項的個數(shù)/從屏幕上面獲得字符并解析,返回在結果表中的表項int start1(FILE *in)char buff20;/用于保存單詞的緩沖區(qū)char nextchar2;char temp20;/用于保存變量或常量的類型數(shù)組int i=0;/緩沖區(qū)指針int a;/比較的結果指針char op3;/用于保存第一個運算符op2='0'nextchar0=fgetc(in);nextchar1='0'while(nextchar0!=EOF)if(isChar(nextchar0)buffi=nextchar0;i+;nextchar0=fgetc(i

14、n);else if(isDigit(nextchar0)buffi=nextchar0;i+;nextchar0=fgetc(in);else if(nextchar0='r'|nextchar0='n')buffi='0'a=isKeyWords(buff);if(a!=-1&&i>0)strcpy(Table1count.value,KeyWordsa.value);Table1count.number=KeyWordsa.number;strcpy(Table1count.description,KeyWordsa.

15、description);count+;/計數(shù)器加一i=0;/清空緩沖區(qū)else if(i>0)if(isChar(buff0)/是標識符strcpy(Variablecount1.value,buff);Variablecount1.number=count1;strcpy(Variablecount1.description,"標識符");count1+;/計數(shù)器加一i=0;/清空緩沖區(qū)else if(isDigit(buff0)/是常量strcpy(Constcount2.value,buff);Constcount2.number=count2;strcpy(

16、Constcount2.description,"常量");count2+;/計數(shù)器加一i=0;/清空緩沖區(qū)else/緩沖區(qū)為空！/處理回車符與換行符nextchar0=fgetc(in);else if(isEndOperation(nextchar0)!=-1)buffi='0'a=isKeyWords(buff);if(a!=-1&&i>0)strcpy(Table1count.value,KeyWordsa.value);Table1count.number=KeyWordsa.number;strcpy(Table1count

17、.description,KeyWordsa.description);strcpy(temp,KeyWordsa.value);count+;/計數(shù)器加一i=0;/清空緩沖區(qū)else if(i>0)if(isChar(buff0)/是標識符strcpy(Variablecount1.value,buff);Variablecount1.number=count1;strcpy(Variablecount1.description,"標識符");count1+;/計數(shù)器加一i=0;/清空緩沖區(qū)else if(isDigit(buff0)/是常量strcpy(Const

18、count2.value,buff);Constcount2.number=count2;strcpy(Constcount2.description,"常量");count2+;/計數(shù)器加一i=0;/清空緩沖區(qū)else/緩沖區(qū)為空！nextchar0=fgetc(in);else if(a=isOperation(nextchar)!=-1)/首先輸出緩沖區(qū)中的數(shù)據(jù)buffi='0'a=isKeyWords(buff);if(a!=-1&&i>0)strcpy(Table1count.value,KeyWordsa.value);Ta

19、ble1count.number=KeyWordsa.number;strcpy(Table1count.description,KeyWordsa.description);count+;/計數(shù)器加一i=0;/清空緩沖區(qū)else if(i>0)if(isChar(buff0)/是標識符strcpy(Variablecount1.value,buff);Variablecount1.number=count1;strcpy(Variablecount1.description,"標識符");count1+;/計數(shù)器加一i=0;/清空緩沖區(qū)else if(isDigit

20、(buff0)/是常量strcpy(Constcount2.value,buff);Constcount2.number=count2;strcpy(Constcount2.description,"常量");count2+;/計數(shù)器加一i=0;/清空緩沖區(qū)else/緩沖區(qū)為空！/處理運算符op0=nextchar0;nextchar0=fgetc(in);if(nextchar0!='')if(isOperation(nextchar)!=-1)op1=nextchar0;if(a=isOperation(op)!=-1)/輸出雙目運算符strcpy(Ta

21、ble1count.value,Operationa.value);Table1count.number=Operationa.number;strcpy(Table1count.description,Operationa.description);count+;/計數(shù)器加一/讀取下一個字符nextchar0=fgetc(in);else/錯誤的雙目運算符strcpy(Table1count.value,op);Table1count.number=-1;strcpy(Table1count.description,"未定義的運算符");count+;/計數(shù)器加一/讀取下

22、一個字符nextchar0=fgetc(in);else/輸出一元運算符op1='0'a=isOperation(op);strcpy(Table1count.value,Operationa.value);Table1count.number=Operationa.number;strcpy(Table1count.description,Operationa.description);count+;/計數(shù)器加一return count;void main()inputKeyWords(WordsBuff,MaxSize1);inputOperation(OperationBuff,MaxSize2);inputEndOperation(EndOperationBuff,MaxSize3);FILE *in,*out;bool Flag=true;while(Flag)printf("源文件的位置：C：input.txtn");if(in=fopen("C:input.txt","r")=NULL)printf("讀取源文件失??！