词法分析程序.doc

1Basedata.h#ifndef _BASETYPE_H#define _BASETYPE_H#define FALSE 0#define TRUE 1#define SPACE 0x20#define BACKSPACE 0x08#define ENTER 0x0d#define ESC 0x1b#define TABLE 0x09 #define ENDFILE -1#endif2Symbol.h #ifndef _SYMBOL_H#define _SYMBOL_H#include #include #define WORDLEN 13 /保留字个数#define MAXIDLEN 50 /标识符最长长度#define SYMBOLNUM 32 /种别码个数typedef enum SYMBOL NOL,IDENT,NUMBER,PLUS,MINUS,TIMES,SLASH, ODDSYM,EQL,NEQ,LSS,LEQ,GTR,GEQ,LPAREN, RPAREN,COMMA,SEMICOLON,PERIOD,BECOMES, BEGINSYM,ENDSYM,IFSYM,THENSYM,WHILESYM, WRITESYM,READSYM,DOSYM,CALLSYM,CONSTSYM, VARSYM,PROCSYM SYMBOL;/定义种别码void Getchar(void);/取下一个字符void Getbc(void);/如当前字符为白字符，则读字符至不为白字符时停止void Concat(void);/将当前字符加入token字void Retract(void);/回退一字符int Reserve(void);/判断token字中单词是否是保留字int Getsym(void);/从当前文件中识别出一单词，并给出其类型和值void Errorsym(void);/打印错误信息#endif3Symbol.c#include basedata.h#include symbol.h#include #include #include char *WORDWORDLEN=BEGIN,CALL,CONST,DO, END,IF,ODD,PROCEDURE, READ,THEN,VAR,WHILE, WRITE ;/保留字字符串表,用于将保留字种别码转为字符串输出SYMBOL WSYMWORDLEN=BEGINSYM,CALLSYM,CONSTSYM, DOSYM,ENDSYM,IFSYM,ODDSYM, PROCSYM,READSYM,THENSYM, VARSYM,WHILESYM,WRITESYM;/保留字种别码表char* SNAMESYMBOLNUM= NOL,IDENT,NUMBER,PLUS,MINUS,TIMES, SLASH,ODDSYM,EQL,NEQ,LSS,LEQ,GTR, GEQ,LPAREN,RPAREN,COMMA,SEMICOLON, PERIOD,BECOMES,BEGINSYM,ENDSYM,IFSYM, THENSYM,WHILESYM,WRITESYM,READSYM, DOSYM,CALLSYM,CONSTSYM,VARSYM,PROCSYM;/单词字符串表,用于将保留字种别码转为字符串输出SYMBOL sym;/最近已识的单词种别码char tokenMAXIDLEN+1;/最近已识别的单词int num;/最近已识别的数字值char ch;/最近已识别的字符int col=1,row=1;/当前行和列值FILE *fd;/指向待编译文件extern FILE *fout;/指向存放结果文件void Getchar(void) ch=fgetc(fd); if(ch!=EOF & ch!=n) col+; return;void Getbc(void) while(ch=SPACE |ch=TABLE |ch=n) if(ch=n) row+;col=1; Getchar();/为空字符则一直读至不为空字符void Retract(void) fseek(fd,-1l,SEEK_CUR); col-;void Concat(void) char temp2; temp0=ch;temp1=0; strcat(token,temp);int Reserve(void) int i,j; char temp60; j=strlen(token); for(i=0;ij;i+) tempi=toupper(tokeni);/将当前token字以大写形式存入temp中 tempi=0; for(i=0;i=WORDLEN) i=-1; return i;void Errorsym(void) fprintf(fout,There is error row: %5d, col: %5d,row,col);int Getsym(void) int k; int flag=TRUE; Getchar(); Getbc();/滤掉白字符 strcpy(token,); if(isalpha(ch) /以字母开头则是标识符 num=0; Concat(); Getchar(); while(isalnum(ch) Concat(); Getchar(); Retract();/由于超前搜索了，所以回退一个字符 k=Reserve();/判断此标识符是否是保留字 if(k!=-1) sym=WSYMk;/将保留字种别码存入sym中 else sym=IDENT;/将一般标识符种别码存入sym中/end else k!=-1;/end of if isalpha else if(isdigit(ch) /以数字开头则为无符号整数Concat();Getchar();while(isdigit(ch) Concat(); Getchar();if(isalpha(ch) flag=FALSE;while(isalnum(ch) Concat(); Getchar(); /end of flag=FALSE Retract();/回退 if(flag)/若是无符号整数，则将整数值存于num中 sym=NUMBER;num=atoi(token); /end of if isdigit else num=0; switch (ch) case +:Concat();sym=PLUS;break; case -:Concat();sym=MINUS;break; case *:Concat();sym=TIMES;break; case /:Concat();sym=SLASH;break; case (:Concat();sym=LPAREN;break; case ):Concat();sym=RPAREN;break; case =:Concat();sym=EQL;break; case #:Concat();sym=NEQ;break;/* ODDSYM,EQL,NEQ,LSS,LEQ,GTR,GEQ,LPAREN, RPAREN,COMMA,SEMICOLON,PERIOD,BECOMES,*/ case ,:Concat();sym=COMMA;break; case .:Concat();sym=PERIOD;break; case ;:Concat();sym=SEMICOLON;break; case : Concat();Getchar(); if(ch!=)/若后不跟=,则回退sym=GTR;Retract(); elseConcat();sym=GEQ; break; case :Concat();Getchar(); if(ch!=)sym=LSS;Retract(); elseConcat();sym=LEQ; break; case :Concat();Getchar(); if(ch!=)flag=FALSE;Retract(); elseConcat();sym=BECOMES; break; default :Concat();flag=FALSE;break; /end of switch else char /end of else char return flag; 4Testsym.c#include basedata.h#include symbol.h#include extern char *WORDWORDLEN;extern int WSYMWORDLEN;extern char* SNAMESYMBOLNUM;extern SYMBOL sym;/last readed word type;extern char tokenMAXIDLEN+1;/last readed wordextern int num;/last readed num;extern char ch;/last readed char;extern int col,row;extern FILE *fd;FILE *fout;void Init(void);void Quit(void);void main() int flag; Init(); fprintf(fout,n TOKEN SYM NUM); doflag=Getsym();if(flag) fprintf(fout,n%10s %10s %d,token,SNAMEsym,num); else if(ch!=EOF) fprintf(fout,n%10s,token); Errorsym(); while(ch!=EOF);/反复调用Getsym()识别单词，将输出结果存入fout中 Quit();/=void Init(void) char temp30; printf(nPlease input your file name:); gets(temp); if (fd = fopen(temp,rt)= NULL) fprintf(stderr, Cannot o